第2个回答 2022-08-16
1since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.
5、用于句型“一段时间+has passed since+时间状语从句”中，译作“自从…以来, …（时间）已经过去了”。