请讲一下BY的用法 是不是有BY一定用完成时呢?
3个回答
1）表示以一般的方法或方式.如：
No one in those days could live by writing poems.
（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?
（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.
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 / by chance / by diligence / by effort / by force / by heart / by luck / by mistake / by hard work.
我可没查字典,BY的用法比较多,我列的是常见的
