since用于什么时态

您好！选 B 【直到现在，独立的词组，用于现在完成时】A D 是过去时的标志。
since （ 自从）+ 过去时的短语或句子。才能用于现在完成时。
如：He has lived here since two years ago .或 He has lived here since he was born .
望采纳 ！谢谢！

since的四种用法

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.
请采纳。