By 与 through 的区别
1．by
（1）表示方法，手段。即“用...， 通过...以…方式
”相当于by means of 如：
All work had to be done by hand 所有的工作都是手工进行的。
He makes a living by teaching 他以教书为生。
It happened through no fault of mine.这件事的发生, 并非由于我的任何过错。
He saluted her by raising his hat.他举起帽子向她致意。
She earned money by writing.她靠写作挣钱。
根据；按照to play by the rules按规则比赛
相差His horse won by a nose.他的马以一鼻之差取胜。
（2）表示传达、传递的方式或煤介。如：
How did you send the letter, by airmail or by ordinary mail?
你是怎么发送的这信，是通过航天邮件还是普通邮件？
（3）表示用交通工具、通讯工具后接名词单数，不加冠词。如：
He came by train, but his wife came by bus. 他是乘火车来的，可是他老婆是坐公共汽车来的。
注意下面两句的区别：
Did you come by train? =Did you come in his car / on my bike?
“by +抽象名词”构成的词组有：
by accident /
1．by
（1）表示方法，手段。即“用...， 通过...以…方式
”相当于by means of 如：
All work had to be done by hand 所有的工作都是手工进行的。
He makes a living by teaching 他以教书为生。
It happened through no fault of mine.这件事的发生, 并非由于我的任何过错。
He saluted her by raising his hat.他举起帽子向她致意。
She earned money by writing.她靠写作挣钱。
根据；按照to play by the rules按规则比赛
相差His horse won by a nose.他的马以一鼻之差取胜。
（2）表示传达、传递的方式或煤介。如：
How did you send the letter, by airmail or by ordinary mail?
你是怎么发送的这信，是通过航天邮件还是普通邮件？
（3）表示用交通工具、通讯工具后接名词单数，不加冠词。如：
He came by train, but his wife came by bus. 他是乘火车来的，可是他老婆是坐公共汽车来的。
注意下面两句的区别：
Did you come by train? =Did you come in his car / on my bike?
“by +抽象名词”构成的词组有：
by accident /