after,before,sinceI saw Bill yesterday,we had not seen each other ( ) i left beijing.这三个单词的用法能详细说明吗?
问题描述：
after,before,since
I saw Bill yesterday,we had not seen each other ( ) i left beijing.
这三个单词的用法能详细说明吗?
答
after表示上次我离开beijing之后就没见到过bill了
before表示我离开北京之前没见过bill
since表示自从我离开北京我就没见过bill了