A relative
clause is a clause that is introduced by a relative word---either
by a relative pronoun or by a relative determiner or by a relative
adverb. Relative clauses may be restrictive or non-restrictive.
When the noun head takes a generic indefinite article or a
cataphoric definite article, the relative clause that follows is
generally a restrictive clause. A double relative clause refers to
a post modifier composed of two relative clauses that share one and
the same antecedent. An embedded relative clause is a clause that
functions both as the post modifier of a noun phrase in the main
clause and as the object of another inserted
clause.
I was sitting
in a chair. It suddenly collapsed.
The chair that I was sitting in suddenly collapsed.
改写定语从句时，要注意那个成分用作定语。
One day in 1906
when he
was crossing a road, Pierre was run over and killed.
One day in 1906, Pierre, who was crossing a road, was run over and
killed.
这句改写是要改成非限定定语从句，要注意非限定定语从句的格式。
He likes
reading, and I am glad to hear that.
He likes reading, which I am glad to hear.
本句中which是代替了前面整句话，相当于as的用法。
My typewriter
is not the machine __(that_)_ it was.
因为that在句中是做补语的作用，所以可以省略。
There was a
certain old man in the village __whom__ none of us liked.
本句中的whom做的是like的宾语，所以要用whom，而不是who。
I cannot
believe that that restaurant _at which__ I have eaten such
wonderful meals, is going to close down.
在饭店吃饭用的介词是at，而不是in。
His thesis, _of
which__ the last hundred pages are absolutely nonsense, will
probably win him a lot of notoriety.
句中，指代的是of his thesis, 要用介词of。
The Tower of
London, _about which__ a lecture is to be given tomorrow, was one
of the world’s historic buildings.
The Tower of London 是一个话题，是关于这个话题的讲座，用about。
We can now see
in a very general way the method _by which_ the computer
works.
句中指的是 work by the method， 用这种方法工作。
She’s about the
only friend of yours _/_ I’ve met _whom_ I really like.
当两个句子处于一个层次时，第一个连接词可以省略，第二个连接词照旧使用。
_B__ the flood,
the ship had reached its destination on time.
A. In case of B. In spite of C.
Because of D. But for
in case of 意为“万一”，because of 意为“由于”，but
for意为“要不是”，引导一虚拟条件句，因而此处缺少一个让步状语，因此B)正确。
Xenon has a
number of applications, __A__ may be mentioned its use in flash
lamps for high speed photography.
A. among which B. which C. and
which D. each of which
此处是which引导的非限制性定语从句，因此，which前不能加连词and
;另外从句句子结构完整，不缺主语和宾语，因此C)和D)不是正确选项。
Take an
umbrella with you in case of _C___.
A. it rains B. the rain C.
rain D. raining
in case of 后要加名词，意为“万一”。
The University
of Georgia, __A__ in 1785, was the first state supported University
in the United States.
A. chartered B. was chartered C. it
was chartered D. to be chartered
在该句中动词应该使用被动式作为主语的修饰成分，即只需直接用过去分词形式。
_A___ that is
found is valuable.
A. Not every pearl B. Every pearl that is
not C. It is not every pearl D.When not every
pearl
句中的that所引导的句子是作定语从句的，因而填入的应为主语。
A historical
novel may do more than mirror history; __B__future events.
A. even influencing B. it may even influence
C. may even influence
D.that it may even influence
句中出现了分号，由分号连接的部分必是句子，因而填入的答案要使后增部分最终成为完整的句子。
A___, glasses
can correct most sight defects in healthy eyes.
A. When well fitted B. Well fitted when C. Well
fitted if D. If well fitted when
原句中已出现完整句子，那么前面填入的只能是从句。When well fitted是 when they are well fitted
的省略形式。
I’ll certainly
work all next week except when it __D__.
A. will be raining B. would rain C.
will rain D. is raining
主句用一般将来时，从句是假设的情况，用一般现在时或现在进行时。
I suppose you
are not going today, __A__?
A. are you B. do you C.
aren’t you D. don’t you
当陈述部分的主句是I suppose, I think, I believe, I
suspect等结构时，附加疑问句部分往往与that分句中的主语和谓语动词保持对应关系。
The size of the
audience, __C__ we had expected, was well over one thousand.
A. whom B. who C. as
D. that
填入的词是用来指代size，因而，不能用whom
和who。that的通常用法是紧跟在指代的词后面，不能有标点符号。因此选项C)正确。
这节课学习了定语从句，定语从句其实我们从高中就开始接触，一直到现在再进一步的学习。知道了定语从句中，如果先行词被两个同一个层次的定语从句修饰时，第一个连接词要省略，第二个连接词可以按照原来的语法法则来使用。定语从句也是需要通过大量的练习来巩固。
