after和since的区别我再完型里总喜欢选错应为带中文意思进去翻译好像都讲得通

since的时态必定是现在完成时和过去完成时:he has taught english since 2000.after后面加一段时间,时态是过去(完成)时,将来时:he will go to the underground station after ten o'clock.he went (has gone)to Pari...