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since的四种用法

作者: admin来源: 网络文章 时间: 2013-02-27

1) since +过去一个时间点 (如具体的年、月、日期、钟点、1980, last month, half past six)。
I have been here since 1989.

2) since +一段时间+ ago
I have been here since five months ago.


3) since +从句 
Great changes have taken place since you left.
Considerable time has elapsed since we have been here.


4) It is +一段时间+ since从句
It is two years since I became a postgraduate student.

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