托福综合写作阅读文本与听力文本
2012-11-08 16:41阅读：
TPO1
Reading
In the United States, employees typically
work five days a week for eight hours each day. However, many
employees want to work a four-day week and are willing to accept
less pay in order to do so. A mandatory policy requiring companies
to offer their employees the option of working a four-day workweek
for four-fifths (80 percent) of their normal pay would benefit the
economy as a whole as well as the individual companies and the
employees who decided to take the option. The shortened workweek
would increase company profits because employees would feel more
rested and alert, and as a result, they would make fewer costly
errors in their work. Hiring more staff to ensure that the same
amount of work would be accomplished would not result in additional
payroll costs because four-day employees would only b
e paid 80 percent of the normal rate. In the end, companies would
have fewer overworked and error-prone employees for the same money,
which would increase company profits. For the country as a whole,
one of the primary benefits of offering this option to employees is
that it would reduce unemployment rates. If many full-time
employees started working fewer hours, some of their workload would
have to be shifted to others. Thus, for every four employees who
went on an 80 percent week, a new employee could be hired at the 80
percent rate. Finally, the option of a four-day workweek would be
better for individual employees. Employees who could afford a lower
salary in exchange for more free time could improve the quality of
their lives by spending the extra time with their families,
pursuing private interests, or enjoying leisure activities.
Listening
Professor
Offering employees the option of a four-day
workweek won't affect the company profits, economic conditions or
the lives of employees in the ways the reading
suggests.
First, offering a four-day workweek will
probably force companies to spend more, possibly a lot more. Adding
new workers means putting much more money into providing training
and medical benefits. Remember the costs of things like health
benefits can be the same whether an employee works four days or
five. And having more employees also requires more office space and
more computers. These additional costs would quickly cut into
company profits.
Second, with respect to overall employment,
it doesn't follow that once some employees choose a four-day
workweek, many more jobs will become available. Hiring new workers
is costly, as I argued a moment ago. And companies have other
options. They might just choose to ask their employees to work
overtime to make up the difference. Worse, companies might raise
expectations. They might start to expect that their four-day
employees can do the same amount of work they used to do in five
days. If this happens, then no additional jobs will be created and
current jobs will become more unpleasant.
Finally, while a four-day workweek offers
employees more free time to invest in their personal lives, it also
presents some risks that could end up reducing their quality of
life. Working a shorter week can decrease employees' job stability
and harm their chances for advancing their careers. Four-day
employees are likely to be the first to lose their jobs during an
economic downturn. They may also be passed over for promotions
because companies might prefer to have five-day employees in
management positions to ensure continuous coverage and consistent
supervision for the entire workweek.
TPO2
Reading
In many organizations, perhaps the best way
to approach certain new projects is to assemble a group of people
into a team. Having a team of people attack a project offers
several advantages. First of all, a group of people has a wider
range of knowledge，expertise, and skills than any single individual
is likely to possess. Also, because of the numbers of people
involved and the greater resources they possess, a group can work
more quickly in response to the task assigned to it and can
come up with highly creative solutions to problems and issues.
Sometimes these creative solutions come about because a group is
more likely to make risky decisions that an individual might not
undertake. This is because the group spreads responsibility for a
decision to all the members and thus no single individual can be
held accountable if the decision turns out to be
wrong.
Taking part in a group process can be very
rewarding for members of the team. Team members who have a voice in
making a decision will no doubt feel better about carrying out the
work that is entailed by the decision than they might doing work
that is imposed on them by others. Also, the individual
team member has a much better chance to “shine”, to get his or her
contributions and ideas not only recognized but recognized as
highly significant, because a team’s overall results can be more
far-reaching and have greater impact than what might have otherwise
been possible for the person to accomplish or contribute working
alone.
Listening
Professor
Now I want to tell you about what one company
found when it decided that it would turn over some of its new
projects to teams of people, and make the team responsible for
planning the projects and getting the work done. After about six
months, the company took a look at how well the teams
performed.
On virtually every team, some members got
almost a 'free ride' . . . they didn't contribute much at all, but
if their team did a good job, they nevertheless benefited from the
recognition the team got. And what about group members who worked
especially well and who provided a lot of insight on problems and
issues? Well . . . the recognition for a job well done went to the
group as a whole, no names were named. So it won't surprise you to
learn that when the real contributors were asked how they felt
about the group process, their attitude was just the opposite of
what the reading predicts.
Another finding was that some projects just
didn't move very quickly. Why? Because it took so long to reach
consensus; it took many, many meetings to build the agreement among
group members about how they would move the project along. On the
other hand, there were other instances where one or two people
managed to become very influential over what their group did.
Sometimes when those influencers said 'That will never work' about
an idea the group was developing, the idea was quickly dropped
instead of being further discussed. And then there was another
occasion when a couple influencers convinced the group that a plan
of theirs was 'highly creative.' And even though some members tried
to warn the rest of the group that the project was moving in
directions that might not work, they were basically ignored by
other group members. Can you guess the ending to this story? When
the project failed, the blame was placed on all the members of the
group.
TPO3
Reading
Rembrandt is the most famous of the
seventeenth-century Dutch painters. However, there are doubts
whether some paintings attributed to Rembrandt were actually
painted by him. One such painting is known as attributed to
Rembrandt because of its style, and indeed the representation of
the woman’s face is very much like that of portraits known to be by
Rembrandt. But there are problems with the painting that suggest it
could not be a work by Rembrandt.
First, there is something inconsistent about
the way the woman in the portrait is dressed. She is wearing a
white linen cap of a kind that only servants would wear-yet the
coat she is wearing has a luxurious fur collar that no servant
could afford. Rembrandt, who was known for his attention to the
details of his subjects’ clothing, would not have been guilty of
such an inconsistency.
Second, Rembrandt was a master of painting light and shadow, but in this
painting these elements do not fit together. The face appears to be
illuminated by light reflected onto it from below. But below the
face is the dark fur collar, which would absorb light rather than
reflect it. So the face should appear partially in shadow-which is
not how it appears. Rembrandt would never have made such an
error.
Finally, examination of the back of the
painting reveals that it was painted on a panel made of several
pieces of wood glued together. Although Rembrandt often painted on
wood panels, no painting known to be by Rembrandt uses a panel
glued together in this way from several pieces of
wood.
For these reasons the painting was removed
from the official catalog of Rembrandt’s paintings in the
1930s.
Listening
Professor:
Everything you just read about 'Portrait of
an Elderly Woman in a White Bonnet' is true, and yet after a
thorough re-examination of the painting, a panel of experts has
recently concluded that it's indeed a work by Rembrandt. Here is
why.
First, the fur collar. X-rays and analysis of
the pigments in the paint have shown that the fur collar wasn't
part of the original painting. The fur collar was painted over the
top of the original painting about a hundred years after the
painting was made. Why? Someone probably wanted to increase the
value of the painting by making it look like a formal portrait of
an aristocratic lady.
Second, the supposed error with light and
shadow. Once the paint of the added fur color was removed, the
original could be seen, in the original painting, the woman is
wearing a simple collar of light-colored cloth. The light-colored
cloth of this collar reflects light that illuminates part of the
woman's face. That's why the face is not in partial shadow. So in
the original painting, light and shadow are very realistic and just
what we would expect from Rembrandt.
Finally, the wood panel. It turns out that
when the fur collar was added, the wood panel was also enlarged
with extra wood pieces glued to the sides and the top to make the
painting more grand and more valuable. So the original painting is
actually painted on a single piece of wood, as would be expected
from a Rembrandt painting. And in fact, researchers have found that
the piece of wood in the original form of 'Portrait of an Elderly
Woman in a White Bonnet' is from the very same tree as the wood
panel used for another painting by Rembrandt, his 'Self-portrait
with a Hat'.
TPO4
Reading
Endotherms are animals such as modern birds
and mammals that keep their body temperatures constant. For
instance, humans are endotherms and maintain an internal
temperature of 37°C, no matter whether the environment is warm or
cold. Because dinosaurs were reptiles, and modern reptiles are not
endotherms, it was long assumed that dinosaurs were not endotherms.
However, dinosaurs differ in many ways from modem reptiles, and
there is now considerable evidence that dinosaurs were, in fact,
endotherms.
Polar dinosaurs
One reason for believing that dinosaurs were
endotherms is that dinosaur fossils have been discovered in polar
regions. Only animals that can maintain a temperature well above
that of the surrounding environment could be active in such cold
climates.
Leg position and movement
There is a connection between endothermy and
the position and movement of the legs. The physiology of endothermy
allows sustained physical activity, such as running. But running is
efficient only if an animal's legs are positioned underneath its
body, not at the body's side, as they are for crocodiles and many
lizards. The legs of all modern endotherms are underneath the body,
and so were the legs of dinosaurs. This strongly suggests that
dinosaurs were endotherms.
Haversian canals
There is also a connection between endothermy
and bone structure. The bones of endotherms usually include
structures called Haversian canals. These canals house nerves and
blood vessels that allow the living animal to grow quickly, and
rapid body growth is in fact a characteristic of endothermy. The
presence of Haversian canals in bone is a strong indicator that the
animal is an endotherm, and fossilized bones of dinosaurs are
usually dense with Haversian canals.
Listening
Professor:
Many scientists have problems with the
arguments you read in the passage. They don't think those arguments
prove that dinosaurs were endotherms.
Take the polar dinosaur argument. When
dinosaurs lived, even the polar regions, where dinosaur fossils
have been found, were much warmer than today, warm enough during
part of the year for animals that were not endotherms to live. And
during the months when the polar regions were cold, the so-called
polar dinosaurs could have migrated to warmer areas or hibernated
like many modern reptiles do. So the presence of dinosaur fossils
in polar regions doesn't prove the dinosaurs were
endotherms.
Well, what about the fact that dinosaurs have
their legs placed under their bodies, not out to the side like
crocodiles. That doesn't necessarily mean dinosaurs were
high-energy endotherms built for running. There is another
explanation for having legs under the body. This body structure
supports more weight, so with the legs under their bodies,
dinosaurs can grow to a very large size. Being large had advantages
for dinosaurs, so we don't need the idea of endothermy and running
to explain why dinosaurs evolved to have their legs under their
bodies.
Ok, so how about bone structure? Many
dinosaur bones do have Haversian canals, that's true. The dinosaur
bones also have growth rings. Growth rings are thickening of the
bone that indicates periods of time when the dinosaurs weren't
rapidly growing. These growth rings are evidence that dinosaurs
stopped growing or grew more slowly during cooler periods. This
pattern of periodic growth, you know, rapid growth followed by no
growth or slow growth, and then rapid growth again, is
characteristic of animals that are not endotherms. Animals that
maintain a constant body temperature year-round as true endotherms
do grow rapidly even when the environment becomes
cool.
TPO5
Reading
As early as the twelfth century A.D., the
settlements of Chaco Canyon in New Mexico in the American Southwest
were notable for their 'great houses,' massive stone buildings that
contain hundreds of rooms and often stand three or four stories
high. Archaeologists have been trying to determine how the
buildings were used. While there is still no universally agreed
upon explanation, there are three competing theories.
One theory holds that the Chaco structures
were purely residential, with each housing hundreds of people.
Supporters of this theory have interpreted Chaco great houses as
earlier versions of the architecture seen in more recent Southwest
societies. In particular, the Chaco houses appear strikingly
similar to the large, well-known 'apartment buildings' at Taos, New
Mexico, in which many people have been living for
centuries.
A second theory contends that the Chaco
structures were used to store food supplies. One of the main crops
of the Chaco people was grain maize, which could be stored for long
periods of time without spoiling and could serve as a long-lasting
supply of food. The supplies of maize had to be stored somewhere,
and the size of the great houses would make them very suitable for
the purpose.
A third theory proposes that houses were used
as ceremonial centers. Close to one house, called Pueblo Alto,
archaeologists identified an enormous mound formed by a pile of old
material. Excavations of the mound revealed deposits containing a
surprisingly large number of broken pots. This finding has been
interpreted as evidence that people gathered at Pueblo Alto for
special ceremonies. At the ceremonies, they ate festive meals and
then discarded the pots in which the meals had been prepared or
served. Such ceremonies have been documented for other Native
American cultures.
Listening
Professor:
Unfortunately none of the arguments about
what the Chaco great houses were used for is
convincing.
First, sure, from the outside, the great
houses look like later and native American apartment building, but
the inside of the great houses casts serious doubt on the idea that
many people lived there. I'll explain. If hundreds of people were
living in the great houses, then there would have to be many
fireplaces, where each family did its daily cooking, but there are
very few fireplaces. In one of the largest great houses, there were
fireplaces for only around ten families. Yet there were enough
rooms in the great house for more than a hundred families, so the
primary function of the houses couldn't have been
residential.
Second, the idea that the great houses were
used to store grain maize is unsupported by evidence. It may sound
plausible that large empty rooms were used for storage, but
excavations of the great houses have not uncovered many traces of
maize or maize containers. If the great houses were used for
storage, why isn't there more spilled maize on the floor? Why
aren't there more remains of big containers?
Third, the idea that the great houses were
ceremonial centers isn't well supported either. You know that mound
at Pueblo Alto? It contains lots of other materials besides broken
pots, stuff you wouldn't expect from ceremonies. For example, there
are large quantities of building materials, sands, stones, even
construction tools. This suggests that the mound is just a trash
heap of construction material, stuff that was thrown away or not
used up when a house was being built. The pots in the pile could be
regular trash too, leftover from the meals of the construction
workers. So the Pueblo Alto mound is not good evidence that the
great houses were used for special ceremonies.
TPO6
Reading
Communal online encyclopedias represent one
of the latest resources to be found on the Internet. They are in
many respects like traditional printed encyclopedias collections of
articles on various subjects. What is specific to these online
encyclopedias, however, is that any Internet user can contribute a
new article or make an editorial change in an existing one. As a
result, the encyclopedia is authored by the whole community of
Internet users. The idea might sound attractive, but the communal
online encyclopedias have several important problems that make them
much less valuable than traditional, printed
encyclopedias.
First, contributors to a communal online
encyclopedia often lack academic credentials, thereby making their
contributions partially informed at best and downright inaccurate
in many cases. Traditional encyclopedias are written by trained
experts who adhere to standards of academic rigor that
nonspecialists cannot really achieve.
Second, even if the original entry in the
online encyclopedia is correct, the communal nature of these online
encyclopedias gives unscrupulous users and vandals or hackers the
opportunity to fabricate, delete, and corrupt information in the encyclopedia.
Once changes have been made to the original text, an unsuspecting
user cannot tell the entry has been tampered with. None of this is
possible with a traditional encyclopedia.
Third, the communal encyclopedias focus too
frequently, and in too great a depth, on trivial and popular
topics, which creates a false impression of what is important and
what is not. A child doing research for a school project may
discover that a major historical event receives as much attention
in an online encyclopedia as, say, a single long-running television
program. The traditional encyclopedia provides a considered view of
what topics to include or exclude and contains a sense of
proportion that online 'democratic' communal encyclopedias do
not.
Listening
Professor:
The communal online encyclopedia will
probably never be perfect, but that's a small price to pay for what
it does offer. The criticisms in the reading are largely the result
of prejudice against and ignorance about how far online
encyclopedias have come.
First, errors. It's hardly a fair criticism
that encyclopedias online have errors. Traditional encyclopedias
have never been close to perfectly accurate, if you are looking for
a realty comprehensive reference work without any mistakes, you are
not going to find it, on or off line. The real point is that it's
easy for errors in factual material to be corrected in an online
encyclopedia. But with the printed and bound encyclopedia, the
errors remain for decades.
Second, hacking. Online encyclopedias have
recognized the importance of protecting their articles from
malicious hackers. One strategy they started using is to put the
crucial facts in the articles that nobody disputes in a read-only
format, which is a format that no one can make changes to. That way
you are making sure that the crucial facts in the articles are
reliable. Another strategy that's being used is to have special
editors whose job is to monitor all changes made to the articles
and eliminate those changes that are clearly
malicious.
Third, what's worth knowing about? The
problem for traditional encyclopedias is that they have limited
space, so they have to decide what's important and what's not. And
in practice, the judgments of the group of academics that make
these decisions don't reflect the great range of interests that
people really have. But space is definitely not an issue for online
encyclopedias. The academic articles are still represented in
online encyclopedias, but there can be a great variety of articles
and topics that accurately reflect the great diversity of users'
interests. The diversity of use in topics that online encyclopedias
offer is one of their strongest advantages
TPO7
Reading
In an effort to encourage ecologically
sustainable forestry practices, an international organization
started issuing certifications to wood companies that meet high
ecological standards by conserving resources and recycling
materials. Companies that receive this certification can attract
customers by advertising their products as eco-certified. Around
the world, many wood companies have adopted new, ecologically
friendly practices in order to receive eco-certification. However,
it is unlikely that wood companies in the United States will do the
same, for several reasons.
First, American consumers are exposed to so
much advertising that they would not value or even pay attention to
the eco-certification label. Because so many mediocre products are
labeled 'new' or improved,'' American consumers do not place much
trust in advertising claims in general.
Second, eco-certified wood will be more
expensive than uncertified wood because in order to earn
eco-certification, a wood company must pay to have its business
examined by a certification agency. This additional cost gets
passed on to consumers-American consumers tend to be strongly
motivated by price, and therefore they are likely to choose cheaper
uncertified wood products. Accordingly, American wood companies
will prefer to keep their prices low rather than obtain
eco-certification
Third, although some people claim that it
always makes good business sense for American companies to keep up
with the developments in the rest of the world, this argument is
not convincing. Pursuing certification would make sense for
American wood companies only if they marketed most of their
products abroad. But that is not the case—American wood businesses
sell most of their products in the United States, catering to a
very large customer base that is satisfied with the
merchandise.
Listening
Well, despite what many people say, there is
a good reason to think that many American wood companies will
eventually seek eco-certification for the wood
products.
First off, companies in the United States
don't treat all advertising the same. They distinguish between
advertising claims that companies make about their own products and
claims made by independent certification agencies. Americans have a
lot of confidence in independent agencies. Thus ecological-minded
Americans are likely to react very favorably to wood products
ecologically certified by independent organization with an
international reputation for trustworthiness.
Second point ,of course it is true that
American consumers care a lot about price ,who doesn't? But studies
of how consumers make decisions show that price alone determines
consumers' decisions only when the price of one competing products
is much higher or lower than the other. When the difference between
two products is small, say, less than 5 percent, as is the case
with certified wood, American often do choose on factories other
than price. And Americans are becoming increasingly convinced of
the value of preserving and protecting the
environment.
And third, US Wood companies should
definitely pay attention what is going on in the wood business
internationally. Not because of foreign consumers but because of
foreign competitors. As I just told you, there is a good chance
that many American consumers will be interested in eco-certified
products, and guess why? If American companies are slow capturing
those consumers, you can be sure that foreign companies will soon
start crowding into the American markets ,offering eco-certified
wood that domestic companies don't.
TPO8
Reading
Toward the end of his life, the
Chevalier de Seingalt (1725-1798) wrote a long memoir recounting his life and
adventures. The Chevalier was a somewhat controversial figure, but
since he met many famous people, including kings and writers, his
memoir has become a valuable historical source about European
society in the eighteenth century. However, some critics have
raised doubts about the accuracy of the memoir. They claim that the
Chevalier distorted or invented many events in the memoir to make
his life seem more exciting and glamorous than it really
was.
For example, in his memoir the Chevalier
claims that while living in Switzerland, he was very wealthy, and
it is known that he spent a great deal of money there on parties
and gambling. However, evidence has recently surfaced that the
Chevalier borrowed considerable sums of money from a Swiss
merchant. Critics thus argue that if the Chevalier had really been
very rich, he would not have needed to borrow money.
Critics are also skeptical about the accuracy
of the conversations that the Chevalier records in the memoir
between himself and the famous writer Voltaire. No one doubts that
the Chevalier and Voltaire met and conversed. However, critics
complain that the memoir cannot possibly capture these
conversations accurately, because it was written many years after
the conversations occurred. Critics point out that it is impossible
to remember exact phrases from extended conversations held many
years earlier.
Critics have also questioned the memoir's
account of the Chevalier's escape from a notorious prison in
Venice, Italy. He claims to have escaped the Venetian prison by
using a piece of metal to make a hole in the ceiling and climbing
through the roof. Critics claim that while such a daring escape
makes for enjoyable reading, it is more likely that the Chevaliers
jailers were bribed to free him. They point out that the Chevalier
had a number of politically well-connected friends in Venice who
could have offered a bribe.
Listening
Professor:
No memoir can possibly be correct in every
detail, but still, the Chevalier's memoir is pretty accurate
overall, and is, by and large, a reliable historical source Let's
look at the accuracy of the three episodes mentioned in the
reading.
First, the loan from the merchant. Well, that
doesn't mean that the Chevalier was poor. Let me explain. We know
that in Switzerland, the Chevalier spent huge amounts of money on
parties and gambling, and he had wealth. But it was a kind of
property you have to sail first to get money. So it usually took a
few days to convert his assets into actual money. So when he ran
out of cash, he had to borrow some while he was waiting for his
money to arrive, but that's not being poor.
Second, the conversations with Voltaire. The
Chevalier states in his memoir that each night immediately after
conversing with Voltaire, he wrote down everything he could
remember about that particular night's conversation. Evidently the
Chevalier kept his notes of these conversations for many years and
referred to them when writing the memoir. Witnesses who lived with
the
Chevalier in his later life confirmed that he
regularly consulted notes and journals when composing the
memoir.
Third, the Chevalier's escape from a prison
in Venice. Other prisoners in that prison had even more powerful
friends than he did, and none of them were ever able to bribe their
way to freedom, So bribery hardly seems likely in his case. The
best evidence, though, comes from some old Venetian government
documents. They indicate that soon after the Chevalier escaped from
the prison, the ceiling of his old prison room had to be repaired.
Why would they need to repair a ceiling unless he had escaped
exactly as he said he did.
TPO9
Reading
Car manufacturers and governments have been
eagerly seeking a replacement for the automobile's main source of
power, the internal-combustion engine. By far the most promising
alternative source of energy for cars is the hydrogen-based
fuel-cell engine, which uses hydrogen to create electricity that,
in turn, powers the car. Fuel-cell engines have several advantages
over internal-combustion engines and will probably soon replace
them.
One of the main problems with the
internal-combustion engine is that it relies on petroleum, either
in the form of gasoline or diesel fuel. Petroleum is a finite
resource; someday, we will run out of oil. The hydrogen needed for
fuel-cell engines cannot easily be depleted. Hydrogen can be
derived from various plentiful sources, including natural gas and
even water. The fact that fuel-cell engines utilize easily
available, renewable resources makes them particularly
attractive.
Second, hydrogen-based fuel cells are
attractive because they will solve many of the world's pollution
problems. An unavoidable by-product of burning oil is carbon
dioxide, and carbon dioxide harms the environment. On the other
hand, the only byproduct of fuel-cell engines is
water.
Third, fuel-cell engines will soon be
economically competitive because people will spend less money to
operate a fuel-cell engine than they will to operate an
internal-combustion engine. This is true for one simple reason: a
fuel-cell automobile is nearly twice as efficient in using its fuel
as an automobile powered by an internal-combustion engine is. In
other words, the fuel-cell powered car requires only half the fuel
energy that the internal-combustion powered car does to go the same
distance.
Listening
Professor:
The reading is correct in pointing out the
problems associated with oil-powered cars. Yes, oil is a finite
resource, and yes, burning oil harms the environment. However, the
reading is way too optimistic in its assessment of hydrogen-based
fuel-cell engines. Hydrogen is not the solution to these
problems.
First, hydrogen is not as easily available as
the passage indicates. Although it's present in common substances
like water, it's not directly useable in that form. For using a
fuel-cell engine, hydrogen must first be obtained in a pure liquid
state. This pure liquid hydrogen is a highly artificial substance.
It's technologically very difficult to produce and store liquid
hydrogen. For example, it must be kept very very cold at minus 253
degrees Celsius. Imagine the elaborate cooling technology that's
required for that! So hydrogen is not such a practical and easily
available substance, is it?
Second, using hydrogen would not solve the
pollution problems associated with cars. Why? Producing pure
hydrogen creates a lot of pollution. To get pure hydrogen from
water or natural gas, you have to use a purification process that
requires lots of energy that's obtained by burning coal or oil. And
burning coal and oil creates lots of pollution. So although the
cars would not pollute, the factories that generated the hydrogen
for the cars would pollute.
Third, there won't necessarily be any cost
savings when you consider how expensive it is to manufacture the
fuel-cell engine. That's because fuel-cell engines require
components made of platinum, a very rare
and expensive metal. Without the platinum components in the engine,
the hydrogen doesn't undergo the chemical reaction that produces
the electricity to power the automobile. All the efforts to replace
platinum with a cheaper material have so far been
unsuccessful.
TPO10
Reading
The sea otter is a small mammal
that lives in waters along the western coast of North America from
California to Alaska. When some sea otter populations off the
Alaskan coast started rapidly declining a few years ago, it caused
much concern because sea otters play an important ecological role
in the coastal ecosystem. Experts started investigating the cause
of the decline and quickly realized that there were two possible
explanations: environmental pollution or attacks by predators.
Initially, the pollution hypothesis seemed the more likely of the
two.
The first reason why pollution seemed the
more likely cause was that there were known sources of it along the
Alaskan coast, such as oil rigs and other sources of industrial
chemical pollution. Water samples from the area revealed increased
levels of chemicals that could decrease the otters' resistance to
life-threatening infections and thus could indirectly cause their
deaths.
Second, other sea mammals such as seals and
sea lions along the Alaskan coast were also declining, indicating
that whatever had endangered the otters was affecting other sea
mammals as well. This fact again pointed to environmental
pollution, since it usually affects the entire ecosystem rather
than a single species. Only widely occurring predators, such as the
orca (a large predatory whale), could have the same effect, but
orcas prefer to hunt much larger prey, such as other
whales.
Third, scientists believed that the pollution
hypothesis could also explain the uneven pattern of otter decline:
at some Alaskan locations the otter populations declined greatly,
while at others they remained stable. Some experts explained these
observations by suggesting that ocean currents or other
environmental factors may have created uneven concentrations of
pollutants along the coast.
Listening
Professor:
Well, ongoing investigations have revealed
that predation is the most likely cause of sea otter decline after
all. Well, ongoing investigations have revealed that predation is
the most likely cause of sea otter decline after all.
First, the pollution theory is weakened by
the fact that no one can really find any dead sea others washing
off on Alaskan beaches. That's not what you would expect if
infections caused by pollution started killing a lot of otters. On
the other hand, the fact that it's so hard to find dead otters is
consistent with the predator hypothesis. If an otter is killed by a
predator, it's eaten immediately so it can't wash up on
shore.
Second, although orcas may prefer to hunt
whales, whales have essentially disappeared from the area because
of human hunters. That means that orcas have had to change their
diet to survive and since only smaller sea mammals are now
available, orcas have probably started hunting those. So it
probably is the orcas that are causing the decline of all the
smaller sea mammals mentioned in the passage - the seals, the sea
lions and the sea otters.
And third, the uneven pattern of otter
decline is better explained by the orca predation theory than by
the pollution theory. What happens to otters seems to depend on
whether the location where they live is accessible to orcas or not.
In those locations that orcas can access easily, the number of sea
otters has declined greatly. However, because orcas are so large,
they can't access shallow or rocky locations. And shallow and rocky
locations are precisely the types of locations where sea otter
populations have not declined.
TPO11
Reading
A recent study reveals that people especially
young people are reading far less literature—novels, plays, and
poems—than they used to. This is troubling because the trend has
unfortunate effects for the reading public, for culture in general,
and for the future of literature itself.
While there has been a decline in book
reading generally, the decline has been especially sharp for
literature. This is unfortunate because nothing else provides the
intellectual stimulation that literature does. Literature
encourages us to exercise our imaginations, empathize with others,
and expand our understanding of language. So by reading less
literature, the reading public is missing out on important
benefits.
Unfortunately, missing out on the benefits of
literature is not the only problem. What are people reading
instead? Consider the prevalence of self-help books on lists of
best sellers. These are usually superficial poorly written, and
intellectually undemanding. Additionally, instead of sitting down
with a challenging novel, many persons are now more likely to turn
on the television, watch a music video, or read a Web page.
Clearly, diverting time previously spent in reading literature to
trivial forms of entertainment has lowered the level of culture in
general.
The trend of reading less literature is all
the more regrettable because it is taking place during a period
when good literature is being written. There are many talented
writers today, but they lack an audience. This fact is bound to
lead publishers to invest less in literature and so support fewer
serious writers. Thus, the writing as well as the reading of
literature is likely to decline because of the poor standards of
today's readers.
Listening
Professor:
It is often said that people are reading less
literature today than they used to. What should of
this?
Well first, a book doesn't have to be
literature to be intellectually stimulating. Science writing
history,. political analysis and so forth aren't literature
perhaps, but they are often of high quality and these kinds of
books can be just as creative and well-written as a novel or a play
They can stimulate the imagination. So don't assume that someone
who isn't reading literature isn’t reading a good
book.
But let's say that people aren't just
spending less time with literature, they are also spending less
time with books in general. Does that mean that the cultures is in
decline? No, there's plenty of culturally valuable material that
isn't written - music and movies, for example. Are people wasting
their time when they listen to a brilliant song or watch a good
movie? Do these non-literary activities lower cultural standards?
Of course not. Culture has changed. In today's culture, there are
many forms of expression available other than novels and poems. And
some of these creative forms speak more directly to contemporary
concerns than literature does.
Finally, it's probably true that there's less
support for literature today than in earlier
generations.
But don't be too quick to blame the readers.
Sometimes it's the author's faults. Let's be honest. A lot of
modern literature is intended to be difficult to understand. Here
is not much reason to suppose that earlier generations of readers
would have read a lot of today's literature either.
TPO12
Reading
Jane Austen (1775-1817) is one of the most
famous of all English novelists, and today her novels are more
popular than ever, with several recently adapted as Hollywood
movies. But we do not have many records of what she looked like.
For a long time, the only accepted image of Austen was an amateur
sketch of an adult Austen made by her sister Cassandra. However
recently a professionally painted, full-length portrait of a
teenage girl owned by a member of the Austen family has come up for
sale. Although the professional painting is not titled Jane Austen,
there are good reasons to believe she is the subject.
First, in 1882, several decades after
Austen's death, Austen's family gave permission to use the portrait
as an illustration in an edition of her letters. Austen's family
clearly recognized it as a portrait of the author. So, for over a
century now, the Austen family itself has endorsed the claim that
the girl in the portrait is Jane Austen.
Second, the face in the portrait clearly
resembles the one in Cassandra's sketch, which we know depicts
Austen. Though somewhat amateurish, the sketch communicates
definite details about Austen's face. Even though the Cassandra
sketch is of an adult Jane Austen, the features are still similar
to those of the teenage girl in the painting. The eyebrows, nose,
mouth, and overall shape of the face are very much like those in
the full-length portrait.
Third, although the painting is unsigned and
undated, there is evidence that it was painted when Austen was a
teenager. The style links it to Ozias Humphrey, a society portrait
painter who was the kind of professional the wealthy Austen family
would hire. Humphrey was active in the late 1780s and early 1790s,
exactly the period when Jane Austen was the age of the girl in the
painting.
Listening
Professor:
The evidence linking this portrait to Jane
Austen is not at all convincing. Sure, the painting has long been
somewhat loosely connected to Austen's extended family and their
descendents, but this hardly proves it's a portrait of Jane Austen
as a teenager. The reading's arguments that the portrait is of
Austen are questionable at best.
First, when the portrait was authorized for
use in the 1882 publication of her letters, Jane Austen had been
dead for almost 70 years. So the family members who asserted that
the painting was Jane had never actually seen her themselves. They
couldn't have known for certain if the portrait was of Austen or
not.
Second, the portrait could very well be that
of a relative of Austen's, a fact that would explain the
resemblance between its subject and that of Cassandra's sketch. The
extended Austen family was very large and many of Jane Austen's
female cousins were teenagers in the relevant period or had
children who were teenagers. And some of these teenage girls could
have resembled Jane Austen. In fact, many experts believe that the
true subject of the portrait was one of those relatives, Marianne
Kempian, who was a distant niece of Austen's.
Third, the painting has been attributed to
Humphrey only because of the style. But other evidence points to a
later date. A stamp on the back of the picture indicates that the
blank canvas, you know the actual piece of cloth on which the
picture was painted, was sold by a man named William Legg. Record
showed that William Legg did not sell canvases in London when Jane
Austen was a teenager. He only started selling canvases when she
was 27 years old. So it looks like the canvas was used for the
painting at a time when Austen was clearly older than the girl in
the portrait.
TPO13
Reading
Private collectors have been selling and
buying fossils, the petrified remains of ancient organisms, ever
since the eighteenth century. In recent years, however, the sale of
fossils, particularly of dinosaurs and other large vertebrates, has
grown into a big business. Rare and important fossils are now being
sold to private ownership for millions of dollars. This is an
unfortunate development for both scientists and the general
public.
The public suffers because fossils that would
otherwise be donated to museums where everyone can see them are
sold to private collectors who do not allow the public to view
their collections. Making it harder for the public to see fossils
can lead to a decline in public interest in fossils, which would be
a pity.
More importantly, scientists are likely to
lose access to some of the most important fossils and thereby miss
out on potentially crucial discoveries about extinct life forms.
Wealthy fossil buyers with a desire to own the rarest and most
important fossils can spend virtually limitless amounts of money to
acquire them. Scientists and the museums and universities they work
for often cannot compete successfully for fossils against
millionaire fossil buyers.
Moreover, commercial fossil collectors often
destroy valuable scientific evidence associated with the fossils
they unearth. Most commercial fossil collectors are untrained or
uninterested in carrying out the careful field work and
documentation that reveal the most about animal life in the past.
For example, scientists have learned about the biology of
nest-building dinosaurs called oviraptors by carefully observing
the exact position of oviraptor fossils in the ground and the
presence of other fossils in the immediate surroundings. Commercial
fossil collectors typically pay no attention to how fossils lie in
the ground or to the smaller fossils that may surround bigger
ones.
Listening
Professor:
Of course there are some negative
consequences of selling fossils in the commercial market, but they
have been greatly exaggerated. The benefits of commercial fossil
trade greatly outweigh the disadvantages.
First of all, the public is likely to have
greater exposure to fossils as a result of commercial fossil trade,
not less exposure. Commercial fossil hunting makes a lot of fossils
available for purchase, and as a result, even low-level public
institutions like public schools and libraries can now routinely
buy interesting fossils and display them for the
public.
As for the idea that scientists will lose
access to really important fossils, that's not realistic
either.
Before anyone can put a value on a fossil, it
needs to be scientifically identified, right? Well, the only people
who can identify fossils, who can really tell what a given fossil
is or isn't, are scientists, by performing detailed examinations
and tests on the fossils themselves. So even if a fossil is
destined to go to a private collector, it has to pass through the
hands of scientific experts first. This way, the scientific
community is not going to miss out on anything important that's out
there.
Finally, whatever damage commercial fossil
collectors sometimes do, if it weren't for them, many fossils would
simply go undiscovered because there aren't that many fossil
collecting operations that are run by universities and other
scientific institutions. Isn't it better for science to at least
have more fossils being found even if we don't have all the
scientific data we'd like to have about their location and
surroundings than it is to have many fossils go completely
undiscovered?
TPO14
Reading
Every year, forest fires and severe storms
cause a great deal of damage to forests in the northwestern United
States. One way of dealing with the aftermath of these disasters is
called salvage logging, which is the practice of removing dead
trees from affected areas and using the wood for lumber, plywood,
and other wood products. There are several reasons why salvage
logging is beneficial both to a damaged forest and to the
economy.
First, after a devastating fire, forests are
choked with dead trees. If the trees are not removed, they will
take years to decompose; in the meantime, no new trees can grow in
the cramped spaces. Salvage logging, however, removes the remains
of dead trees and makes room for fresh growth immediately, which is
likely to help forest areas recover from the
disaster.
Also, dead trees do more than just take up
space. Decaying wood is a highly suitable habitat for insects such
as the spruce bark beetle, which in large numbers can damage live,
healthy spruce trees. So by removing rotting wood, salvage logging
helps minimize the dangers of insect infestation, thus contributing
to the health of the forest.
Third and last, salvage logging has economic
benefits. Many industries depend upon the forests for their
production, and because of this a fire can have a very harmful
effect on the economy. Often, however, the trees that have been
damaged by natural disasters still can provide much wood that is
usable by industries. Furthermore, salvage logging requires more
workers than traditional logging operations do, and so it helps
create additional jobs for local residents.
Listening
Professor:
Salvage logging may appear to be an effective
way of helping forests recover after a destructive fire or storm,
but it can actually result in serious longer-term environmental
damage Its economic benefits are also questionable.
First, cleaning up a forest after a fire or
storm does not necessarily create the right conditions for tree
growth. In fact, the natural process of wood decomposition enriches
the soil and makes it more suitable for future generations of tree.
The rapid removal of dead trees can result in soil that lacks the
nutrients necessary for growth.
Second, it's true that rotting wood can
increase insect populations, but is this really bad for the forest?
In fact, spruce bark beetles have lived in Alaskan forest for
nearly a hundred years without causing major damage. And of course
dead trees do not provide habitats only for harmful insects. They
are also used by birds and other insects that are important
contributors to the long-term health of forests. In the long run,
therefore, salvage logging may end up-doing more harm to forests
than harmful insects do.
And third, the economic benefits of salvage
logging are small and do not last very long, in severely damaged
forests, much of the lumber can be recovered only by using
helicopters and other vehicles that are expensive to use and
maintain. Furthermore, jobs created by salvage logging are only
temporary and are often filled by outsiders with more experience or
training than local residents have.
TPO15
Reading
The cane toad is a large (1.8 kg)
amphibian species native
to Central and South America. It was deliberately introduced to
Australia in 1935 with the expectation that it would protect
farmers' crops by eating harmful insects.
Unfortunately, the toad multiplied rapidly, and a large cane toad
population now threatens small native animals that are not pests.
Several measures have been proposed to stop the spread of the cane
toad in Australia.
One way to prevent the spread of the toad
would be to build a national fence. A fence that blocks the advance
of the toads will prevent them from moving into those parts of
Australia that they have not yet colonized. This approach has been
used before: a national fence was erected in the early part of the
twentieth century to prevent the spread of rabbits, another animal
species that was introduced in Australia from abroad and had a
harmful impact on its native ecosystems.
Second, the toads could be captured and
destroyed by volunteers. Cane toads can easily be caught in simple
traps and can even be captured by hand. Young toads and cane toad
eggs are even easier to gather and destroy, since they are
restricted to the water. If the Australian government were to
organize a campaign among Australian citizens to join forces to
destroy the toads, the collective effort might stop the toad from
spreading.
Third, researchers are developing a
disease-causing virus to control the cane toad populations. This
virus will be specially designed: although it will be able to
infect a number of reptile and amphibian species, it will not harm
most of the infected species; it will specifically harm only the
cane toads. The virus will control the population of cane toads by
preventing them from maturing and reproducing.
Listening
The cane toad won’t be as easy to get rid of
as the reading suggests. The measures proposed by the reading are
likely either to be unsuccessful or to cause unwanted environmental
damage.
First of all, a national fence probably won’t
stop the spread of the toad. That’s because young toads and toad
eggs are found in rivers and streams. No matter where the fence is
located, at some point there will be rivers or streams flowing from
one side to the other. These waterways will be able to carry the
young toads and their eggs to the other side. Since it’s only
necessary for a few young toads or eggs to get through the fence in
order to establish population on the other side, the fence is
unlikely to be effective.
Secondly, a massive group of volunteers could
have success trapping and destroying toads. But it’s likely that
these untrained volunteers would inadvertently destroy many of
Australia’s native frogs. Some of which are endangered. It’s not
always easy to tell the cane toad apart from native frogs
especially when it’s young.
Third, using the virus is a bad idea because
it could have terrible consequences for cane toads in their
original habitat in Central and South America. You might be
wondering how can a virus released in Australia cause harm in the
America. Well, Australian reptiles and amphibians are often
transported to other continents by researchers or pet collectors
for example. Once the animals infected by the virus reach Central
and South America, the virus will attack the native cane toads and
devastate their populations. That would be and ecological disaster
because in the America cane toads are a native species and a vital
part of the ecosystem. So if they are eliminated, the whole
ecosystem will suffer.
TPO16
Reading
The United Kingdom (sometimes referred to as
Britain) has a long and rich history of human settlement. Traces of
buildings, tools, and art can be found from periods going back many
thousands of years: from the Stone Age, through the Bronze Age, the
Iron Age, the time of the Roman colonization, the Middle Ages, up
to the beginnings of the industrial age. Yet for most of the
twentieth century, the science of archaeology—dedicated to
uncovering and studying old cultural artifacts—was faced with
serious problems and limitations in Britain.
First, many valuable artifacts were lost to
construction projects. The growth of Britain's population,
especially from the 1950s on, spurred a lot of new construction in
British cities, towns, and villages. While digging foundations for
new buildings, the builders often uncovered archaeologically
valuable sites. Usually, however, they proceeded with the
construction and did not preserve the artifacts. Many
archaeologically precious artifacts were therefore
destroyed.
Second, many archaeologists felt that the
financial support for archaeological research was inadequate. For
most of the twentieth century, archaeology was funded mostly
through government funds and grants, which allowed archaeologists
to investigate a handful of the most important sites but which left
hundreds of other interesting projects without support.
Furthermore, changing government priorities brought about
periodic reductions in
funding.
Third, it was difficult to have a career in
archaeology. Archaeology jobs were to be found at universities or
with a few government agencies, but there were never many positions
available. Many people who wanted to become archaeologists ended up
pursuing other careers and contributing to archaeological research
only as unpaid amateurs.
Listening
In 1990, new rules and guidelines were
adopted in United Kingdom and that had changed the whole feel of
Archaeology in that country. The new guidelines improved the
situation in all 3 areas discussed in the passage.
First, the new guidelines state that before
any construction project can start, the construction site has to be
examined by archaeologists to see whether the site is of
archaeological interest or value. If the site is of archaeological
interest, the next step is for the builders, archaeologists and
local government officials to get together and make a plan for
preserving the archaeological artifacts, either by building around
them or by excavating a document in them properly before the
construction is allowed to proceed.
Second, an important part of new guidelines
is the rule that any archaeological work done on the construction
site will be paid for by the construction company not by the
government. The construction company has to pay for the initial
examination of the site, and then for all the work carried out
under the preservation plan. This is whole new source of financial
support. The funding from the construction company has allowed
researchers to study a far great range of archaeological sites than
they could in past.
Last, the new guidelines provide a lot of
paid work for archaeologists, work that didn’t exist before. Expert
archaeologists are now hired all stage of the process to examine
the site for archaeological value, then have to drop the
preservation plan to do the researcher and professional scientific
manner and finally to process the data and write reports and
articles. The increased job career opportunities in Archaeology
have increased the number professional archaeologists in Britain
which is now the highest it’s ever been.
TPO17
Reading
In the past century, the steady growth of the
human population and the corresponding increase in agriculture and
pesticide use have caused much harm to wildlife in the United
States—birds in particular. Unfortunately for birds, these trends
are likely to continue, with the result that the number of birds in
the United States will necessarily decline.
First, as human populations and settlements
continue to expand, birds' natural habitats will continue to
disappear. Forests, wetlands, and grasslands will give way to ever
more homes, malls, and offices. As the traditional areas suitable
for birds keep decreasing, so will the size of the bird populations
that depend on those vanishing habitats.
Second, agricultural activities must increase
to keep pace with the growing human population. The growth of
agriculture will also result in the further destruction of bird
habitats as more and more wilderness areas are converted to
agricultural use. As a result, bird populations in rural areas will
continue to decline.
Third, as human settlements expand and
agriculture increases, the use of chemical pesticides will also
increase. Pesticides are poisons designed to kill agricultural and
home garden pests, such as insects, but inevitably, pesticides get
into the water and into the food chain for birds where they can
harm birds. Birds that eat the poisoned insects or drink
contaminated water can die as a result, and even if pesticides do
not kill birds outright, they can prevent them from reproducing
successfully. So pesticides have significantly contributed to
declines in bird population, and because there will continue to be
a need to control agricultural pests in the future, this decline
will continue.
Listening
The passage clams that there will be fewer
and fewer birds, but the arguments used to support this claim are
unconvincing.
First, it’s true that urban growth has been
bad for some types of birds, but urban development actually
provides better and larger habitats for other types, so much so
that city and suburban dwellers often complain about increased
birds populations—seagulls at landfills, pigeons on the streets and
so on. Even birds like hawks and falcons can now be found in
cities, where they prey on the increasing populations of pigeons
and rodents. So it’s not going to be a story of uniform decline of
bird populations in the future. Some populations may shrink, but
others will grow.
As for agriculture, it’s true that it too
will increase in the future, but not in the way assumed by the
reading passage. The truth is, in the United States, less and less
land is being used for agriculture every year. Increasing in
agricultural production have resulted from and will continue to
result from the introduction of new, more productive varieties of
crops. These new crops produce more food per unit of land, and as a
result, there’s no need to destroy wilderness areas.
And third, while it’s certainly true that
traditional pesticides have been destructive to birds, it’s
incorrect to project this history into the future. Now that people
are aware of the possible consequences of traditional pesticides,
two changes have occurred. First, new and much less toxic
pesticides have been developed, and that’s important. Second, and
perhaps more importantly there is a growing trend to develop more
pest resistant crops, crops that are genetically designed to be
unattractive to pests. Pest resistant crops greatly reduce the need
for chemical pesticides. And best of all, pest resistant crops
don’t harm birds at all.
TPO18
Reading
In the 1950s Torreya taxifoha, a type of
evergreen tree once very common in the state of Florida, started to
die out. No one is sure exactly what caused the decline, but
chances are good that if nothing is done, Torreya will soon become
extinct. Experts are considering three ways to address the decline
of Torreya.
The first option is to reestablish Torreya in
the same location in which it thrived for thousands of years.
Torreya used to be found in abundance in the northern part of
Florida, which has a specific microclimate. A microclimate exists
when weather conditions inside a relatively small area differ from
the region of which that area is a part. Northern Florida's
microclimate is very favorable to Torreya's growth. This
microclimate is wetter and cooler than the surrounding region's
relatively dry, warm climate. Scientists have been working to plant
Torreya seeds in the coolest, dampest areas of the
microclimate.
The second option is to move Torreya to an
entirely different location, far from its Florida microclimate.
Torreya seeds and saplings have been successfully planted and grown in forests
further north, where the temperature is significantly cooler. Some
scientists believe that Torreya probably thrived in areas much
further north in the distant past, so by relocating it now, in a
process known as assisted migration, humans would simply be helping
Torreya return to an environment that is more suited to its
survival.
The third option is to preserve Torreya in
research centers. Seeds and saplings can be moved from the wild and
preserved in a closely monitored environment where it will be
easier for scientists both to protect the species and conduct
research on Torreya. This research can then be used to ensure the
continued survival of the species.
Listening
You’ve just read about three ways to save
Torreya taxifolia. Unfortunately, none of these three options
provides a satisfactory solution.
About the first solution-reestablishing
Torreya in the same location-that’s unlikely to be successful,
because of what’s happening to the coolest dampest areas within
torreya’s micro-climate. These areas are being strongly affected by
changes in the climate of the larger region. This could be because
global warming has contributed to an increase in overall
temperatures in the region or because wetlands throughout Florida
have been drained. Either way, many areas across the region are
becoming drier, so it’s unlikely that Torreya would have the
conditions it needs to survive anywhere within its original Florida
micro-climate.
Now about the second solution, relocating
Torreya far from where it currently grows, well, let’s look at what
happened when humans helped another tree, the black locust tree,
move north to a new environment. When they did this, the black
locust tree spread so quickly that it killed off many plants and
trees in the new environment, and some of these plants and trees
were themselves already in danger of becoming extinct . So assisted
migration can have unpredicted outcomes for the new
environment.
Third, research centers are probably not a
solution either. That’s because the population of Torreya trees
that can be kept in the centers will probably not be able to resist
diseases. For a population of trees to survive a disease, it needs
to be relatively large and it needs to be genetically diverse. Tree
populations in the wild usually satisfy those criteria but research
centers would simply not have enough capacity to keep a large a
diverse population of Torreya trees, so trees in such centers will
not be capable of surviving diseases in the long term.
TPO19
Reading
Many consumers ignore commercial
advertisements. In response, advertising companies have started
using a new tactic, called “buzzing.' The advertisers hire
people,buzzers,who personally promote (buzz) products to people
they know or meet. The key part is that the buzzers do not reveal
that they are being paid to promote anything. They behave as though
they were just spontaneously praising a product during normal
conversation. Buzzing has generated a lot of controversy, and many
critics would like to see it banned.
First, the critics complain that consumers
should know whether a person praising a product is being paid to
praise the product. Knowing this makes a big difference: we expect
the truth from people who we believe do not have any motive for
misleading us. But with buzzing what you hear is just paid
advertising, which may well give a person incorrect information
about the buzzed product.
Second, since buzzers pretend they are just
private individuals, consumers listen to their endorsements less
critically than they should. With advertisements in print or on TV,
the consumer is on guard for questionable claims or empty
descriptions such as 'new and improved.' But
when consumers do not know they are being lobbied, they may accept
claims they would otherwise be suspicious of.
This may suit the manufacturers, but it could
really harm consumers.
And worst of all is the harmful effect that
buzzing is likely to have on social relationships. Once we become
aware that people we meet socially may be buzzers with a hidden
agenda, we will become less trustful of people in general. So
buzzing will result in the spread of mistrust and the expectation
of dishonesty.
Listening
Hi, my name is Bill. Um, I was talking your
professor in the subway about the great phone service that I was
using. And it turned out we’re both interested in marketing. So he
asked me to talk in his marketing classes. You see, I am a buzzer,
part time, you know. During the day, I’m a student just like you.
Now, I read that piece attacking buzzing, it is really misleading.
How would it describe buzzing leading a lot, and gives a wrong
impression?
First, it makes it sound like buzzers don’t
tell the truth about the products they’re buzzing. That’s not true.
How buzzing works this. Companies find people who use their
products and who really think product is good. So buzzing is not
like ordinary advertisement where an actress is paid to read some
lies. Um, yes, I get paid for telling you what I am thinking, but
you get the truth from buzzers. I really do think my phone service
is great. That is why the company hired me.
Second, the reading makes it seem that when a
buzzer talks to someone, the person believes whatever they hear
from the buzzer. Not true. In fact, the opposite is true. People I
talk to ask a lot of questions about the products I buzz, that is
about the price, service and how long I used the product. If I
don’t have good answers, they won’t buy the products.
Finally, if you believe what you read,
buzzing will destroy civilization, that is stupid. If a product is
bad, the company can’t recruit buzzers. So what you get from a
buzzer is not only sincere but is likely to be about a good
product. If you try the phone service I use, you’re gonna love it.
So people who try buzzed products are going to have a good
experience. So end up being more trustful and open up to
people.
TPO20
Reading
In the United States, it had been common
practice since the late 1960s no to suppress natural forest fires.
The “let it burn” policy assumed that forest fire would burn
themselves out quickly, without causing much damage. However, in
the summer of 1988, forest fires in Yellowstone, the most famous
national park in the country, burned for more than two months and
spread over a huge area, encompassing more than 800,000 acres.
Because of the large scale of the damage, many people called for
replacing the “let it burn” policy with a policy of extinguishing
forest fires as soon as they appeared. Three kinds of damage caused
by the “let it burn” policy were emphasized by critics of the
policy.
First, Yellowstone fires caused tremendous
damage to the park’s trees and other vegetation. When the fires
finally died out, nearly one third of Yellowstone’s land had been
scorched. Trees were charred and blackened from flames and smoke.
Smaller plants were entirely incinerated. What had been a national
treasure now seemed like a devastated wasteland.
Second, the park wildlife was affected as
well. Large animals like deer and elk were seen fleeing the fire.
Many smaller species were probably unable to escape. There was also
concern that the destruction of habitats and the disruption of food
chains would make it impossible for the animals that survived the
fire to return.
Third, the fires compromised the value of the
park as a tourist attraction, which in turn had negative
consequences for the local economy. With several thousand acres of
the park engulfed in flames, the tourist season was cut short, and
a large number of visitors decided to stay away. Of course, local
businesses that depended on park visitors suffered as a
result.
Listening
Actually fires are natural part of ecological
cycle and their role is not just destructive but also creative.
That is why the “let it burn” policy is fundamentally a good one,
even if it sometimes causes fires of the 1988 Yellowstone fire.
Let’s look at what happened after 1988 Yellowstone
fire.
First, vegetation. As you might imagine,
scorched areas were in time colonized by new plants. As a matter of
fact, the plants in Yellowstone became more diverse because the
fire created an opportunity for certain plants that could not grow
otherwise. For example, areas where the trees have been destroyed
by fire could now be taken over by smaller plants that needed open
and shaded space to grow. And another example, seeds of certain
plants species won’t germinate unless they’re exposed to very high
levels of heat. So, those plants started appearing after the fire
as well.
It’s a similar story with the animals. Not
only did their population recover, but the fire also created new
opportunities. For instance, the small plants that replaced trees
after the fire created an ideal habitat for certain small animals
like rabbits and hares. And when rabbits and hares started
thriving, so did some predators that depended on them for food. So,
certain food chains actually became stronger after the fire than
they were before.
And last, fires like 1988 Yellowstone fire
would be a problem for tourism if they happened every year. But
they don’t. it was a very unusual combination of factors that year,
low rainfall, unusually strong winds, accumulation of dry
undergrowth that caused fire to be so massive. This combination has
not occurred since and Yellowstone has not seen such a fire since
1988. Visitors came back to the park next year and each year after
that.
TPO21
Reading
Genetic modification, a process used to
change an organism’s genes and hence its characteristics, is now
being used to improve trees through genetic modification. It is
possible to create trees that produce more fruit, grow faster, or
withstand adverse conditions. Planting genetically modified trees
on a large scale promises to bring a number of
benefits.
First, genetically modified trees are
designed to be hardier than nature trees; that is, they are more
likely to survive than their unmodified counterparts. In Hawaii,
for example, a new pest-resistant species of papaya trees has been
developed in response to ring spot virus infections that have
repeatedly damaged the native papaya tree population. Planting the
genetically modified papayas has largely put an end to the ring
spot problem.
Moreover, genetically modified trees promise
to bring a number of economic benefits to those who grow them.
Genetically modified trees tend to grow faster, give greater yields
of food, fruit, or other products and be hardier. This allows tree
farmer to get faster and greater returns on their farming
investment and save on pesticides as well.
Finally, the use of genetically modified
trees can prevent overexploitation of wild trees. Because of the
growing demand for firewood and building timber, many forests
around the world are being cut down faster than they can be
replaced. Introducing genetically modified trees, designed for fast
growth and high yield in given geographic conditions, would satisfy
the demand for wood in many of those areas and save the endangered
native trees, which often include unique or rare
species.
Listening
Sure, there are some benefits to plant
genetically modified trees, but, are these trees as really great as
they first sound? When you examine the subject firstly, there are
some serious problems and costs associated with genetically
modified trees.
First, genetically modified trees may be
resistant to one particular condition. But that doesn’t necessarily
ensure their survival. You see, a typical non modified trees’
population is genetically diverse. That means that for most
threatening conditions, or climate, whatever, there will be at
least some individual tress of any given species of tree that are
resistant. So even if most of one kind of trees are killed, those
few resistant tress will survive and ensure the survival of that
species of tree. But genetically modified trees are genetically
much more uniform. So if they’re exposed to an environmental
challenge they have not been designed for, they all die. So if the
climate changes, the genetically modified trees will likely to be
completely wiped out.
Now as to the second point, they’re hidden
costs associated with genetically modified trees. You see, the
company that genetically modify the tree can charge tree farmers
more for its seeds than un- genetically modified trees would cost.
Also, as you’ve grown the tree, you can’t just collect the seeds
and plant the new tree for free. By law, you have to pay the
company every time you plant.
And finally, genetically modified trees might
actually cause even more damage to the local wild trees. You see,
genetically modified trees often grow more aggressively than
natural trees do. And, genetically modified trees are typically
planted among natural trees. As a result, the genetically modified
trees outcompete the native trees for resources, sunlight, soil,
nutrients, and water, eventually crowding out the natural
trees.
TPO22
Reading
Ethanol fuel, made from plants such as corn
and sugar cane, has been advocated by some people as an alternative
to gasoline in the United States. However, many critics argue that
ethanol is not a good replacement for gasoline for several
reasons.
First, the increased use of ethanol fuel
would not help to solve one of the biggest environmental problems
caused by gasoline use: global warming. Like gasoline, ethanol
releases carbon dioxide into the atmosphere when it is burned for
fuel and carbon dioxide is greenhouse gas: it helps trap heat in
the atmosphere. Thus, ethanol offers no environmental advantage
over gasoline.
Second, the production of significant amounts
of ethanol would dramatically reduce the amount of plants available
for uses other fuel. For example, much of the corn now grown in the
United States is used to feed farm animals such as cows and
chickens. It is estimated that if ethanol were used to satisfy just
10 percent of the fuel needs in the United States, more than 60
percent of the corn currently grown in the united stated would have
to be used to produce ethanol. If most of the corn were used to
produce ethanol, a substantial source of food for animals would
disappear.
Third, ethanol fuel will never be able to
compete with gasoline on price. Although the prices of ethanol and
gasoline for the consumer are currently about the same, this is
only because of the help in the form of tax subsidies given to
ethanol producers by the United States government. These tax
subsidies have cost the United States government over $11 billion
in the past 30 years. If the United States government were to stop
helping producers in this way, the price of ethanol would increase
greatly.
Listening
Ethanol actually is a good alternative to
gasoline, although you just read three reasons why it’s not a good
alternative, not one of these three reasons is
convincing.
First, the increased use of Ethanol fuel will
not add to global warming. It’s true that, when Ethanol is burned,
it releases carbon dioxide into the atmosphere, but as you read,
Ethanol is often made from plants such as corn. Well, the process
of growing the plants counteracts this release of carbon dioxide.
Let me explain. Every growing plant absorbs carbon dioxide from the
air as part of its nutrition. So growing plants for Ethanol
production actually removes carbon dioxide from the
atmosphere.
Second, large scale production of Ethanol
doesn’t have to reduce the sources of food for animals. That’s
because we can produce Ethanol using cellulose, cellulose is the
main component of plants’ cell walls, and you’ll find most
cellulose in those parts of plants that are not eaten by animals.
So, since we can produce Ethanol from the plant parts that aren’t
eaten, the amount of animal feed that is available will not be
reduced.
Third, in the future, Ethanol will be able to
compete with gasoline in terms of price. It’s true that government
subsidies make Ethanol cheaper than it would normally be, but this
support won’t always be needed. Once enough people start buying
Ethanol, Ethanol producers will increase their production of
Ethanol. Generally, increased production of products leads to a
drop in its price. So the price of Ethanol will go down as more of
it becomes available. Studies show that, if Ethanol production
could be three times greater than it is now, the cost of producing
a unit of Ethanol will drop by forty percent.
TPO23
Populations of the yellow cedar, a species of
tree that is common in northwestern North America, have been
steadily declining for more than a century now, since about 1880.
Scientists have advanced several hypotheses explain this
decline.
One hypothesis is that the yellow cedar
decline may be caused by insect parasites, specifically the cedar
bark beetle. This beetle is known to attack cedar trees; the beetle
larvae eat the wood. There have been recorded instances of
sustained beetle attacks overwhelming and killing yellow cedars, so
this insect is a good candidate for the cause of the tree’s
decline.
A second hypothesis attributes the decline to
brown bears. Bears sometimes claw at the cedars in order to eat the
tree bark, which has a high sugar content. In fact, the cedar bark
can contain as much sugar as the wild berries that are a staple of
the bears’ diet. Although the bears’ clawing is unlikely to destroy
trees by itself, their aggressive feeding habits may critically
weaken enough trees to be responsible for the decline.
The third hypothesis states that gradual
changes of climate may be to blame. Over the last hundred years,
the patterns of seasonal as well as day-to-day temperatures have
changed in northwestern North America. These changes have affected
the root systems of the yellow cedar trees: the fine surface roots
now start growing in the late winter rather than in the early
spring. The change in the timing of root growth may have
significant consequences. Growing roots are sensitive and are
therefore likely to suffer damage from partial freezing on cold
winter nights. This frozen root damage may be capable of
undermining the health of the whole tree, eventually killing
it.
Listening
Unfortunately, we still don’t know what’s
killing the yellow cedar, none of the explanations discussed in the
reading is adequate.
First, the cedar bark beetle. Well, the
problem with this explanation is that healthy yellow cedars are
generally much more resistant to insect infestation than other tree
species. For example, the bark and leaves of yellow cedar are
saturated with powerful chemicals that are poisonous to insects.
So, healthy cedars are unlikely to suffer from insect damage. So,
how can we explain those dead cedars that were infested with
beetles. In those cases, the beetles attack trees that were already
damaged or sick, and would’ve probably died anyway. So, the beetles
are not the fundamental cause responsible for the decline of yellow
cedars.
Second, although bears damage some trees,
there’re not the cause of the overall population decline. Yellow
cedar population’s been declining all across the northwestern coast
of North America both on the mainland and on islands just off the
coast. There were no bears on the islands, yet the islands cedars
are still in decline. Since the decline occurs with and without
bears, the bears cannot be responsible.
And finally, the theory about roots suffering
from frost damage, well, the reading passage forgot to take one
factor into account. Many more trees are dying at lower elevations
where it is warm than at higher elevations where it is cold. If
freezing damage were responsible for the decline, we could expect
to see more trees dying in the cold weather of higher elevations.
Instead, more trees are dying in the relative warmth of the lower
elevations. So, although the climate change may have made the cedar
roots more sensitive than it used to be, this isn’t what’s killing
them.
TPO24
Reading
Animal fossils usually provide very little
opportunity to study the actual animal tissues, because in fossils
the animals' living tissues have been largely replaced by minerals.
Thus, scientists were very excited recently when it appeared that a
70-million-year-old fossil of Tyrannosaurus rex (T. rex), a
dinosaur, might still contain remains of the actual tissues of the
animal. The discovery was made when researchers deliberately broke
open the T. rex’s leg bone, thereby exposing its insides to reveal
materials that seem to be remains of blood vessels, red blood
cells, and collagen matrix.
First, the breaking of the fossilized leg
bone revealed many small branching channels inside, which probably
correspond to hollows in the bones where blood vessels were once
located. The exciting finding was the presence of a soft, flexible
organic substance inside the channels. This soft substance may very
well represent the remains of the actual blood vessels of T. rex.
Second, microscopic examination of the
various parts of the inner bone revealed the presence of spheres
that could be the remains of red blood cells. Tests showed that the
spheres contained iron-a material vital to the role of red blood
cells in transporting oxygen to tissues. Moreover, the
spheres had dark red centers (substances with iron tend to be
reddish in color) and were also about the size of red blood
cells.
Third, scientists performed a test on the
dinosaur leg bone that showed that it contained collagen. Collagen
is a fibrous protein that is a main component of living bone
tissue, in which it forms a so-called collagen matrix. Collagen (or
its chemical derivatives) is exactly the kind of biochemical
material that one would expect to find in association with bone
tissue.
Listening
As much as we would like to have the remains
of actual dinosaur tissue, there are sound reasons for being
skeptical of the identifications made in the reading.
First, the soft, flexible substance inside
the bone channels isn’t necessarily the remains of blood vessels.
It is much more likely to be something else. Like what? You might
say. Well, long after an organism is died, bacteria sometimes
colonize hollows, empty areas in bones, like the channels that once
held blood vessels. When bacteria lived inside bones, they often
leave behind traces of organic material. What the researchers in
the reading are identifying as blood vessels might just be traces
of soft and moist residue left by bacteria colonies.
All right. What about the iron-filled
spheres? Well, the problem is that scientists found identical
reddish spheres in fossils of other animals found in the same
place. That includes fossils of primitive animals that did not have
any red blood cells when they were alive. Clearly, if these spheres
appear in organisms that did not have any red blood cells, then the
spheres cannot be the remains of red blood cells. The spheres
probably have a very different origin. They are probably just
pieces of reddish mineral.
Third, the collagen. The problem is that we
have never found collagen in animal remains that are older than one
hundred thousand years. Collagen probably cannot last longer than
that. Finding collagen from an animal that lived seventy million
years ago would really contradict our ideas about how long collagen
can last. It is just too improbable. The most likely explanation
for the presence of collagen is that it doesn’t come from the
T.rex, but from another much more recent source. For example, human
skin contains collagen, so the collagen may have come from the skin
of the researchers who are handling the bone.
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