英语，初三

来源：百度知道 编辑：UC知道 时间：2024/09/21 02:38:07
Ten years______since my uncle ________to america
Apassed:went B has passed:went
Cpassed:has gone D has passed;has gone
请解释一下为什么不选c而选b 拜谢
还是不懂吖since的那种用法吖？

首先是since的用法
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.

其次是时态搭配问题

现在完成时可以用来表示发生在过去某一时刻的,持续到现在的情况,常与for,since连用.

从句since my uncle went to amercia是作为过去某一时刻，时态用一般过去时。
从叔叔去美国这一点开始，到现在已经有十年了。时态用现在完成时态。

看到since，很多时候都应该用完成时。

since的用法如此