since+ 时间点,for+时间段,already,yet,ever,never,so far,until now,up to now,recently,t hese days/weeks/years,always,in the last/past( few years)
这些词出现时常用现在完成时.也不是特别绝对.
since+ 时间点,for+时间段,already,yet,ever,never,so far,until now,up to now,recently,t hese days/weeks/years,always,in the last/past( few years)
这些词出现时常用现在完成时.也不是特别绝对.