蝈蝈熊
幼苗
共回答了16个问题采纳率:93.8% 举报
应该选C
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.
before表示从过去或将来某一时间算起多少时间以前,由于与这一时间状语连用的行为先发生在过去或将来某一时刻之前,因此往往出现在过去完成时态或将来完成时态中.例如:
① I called him up last night, but his mother told me he had left for Wuhan two days before.
② She said that she had married him five years before.
1年前
5