A.after B.before C.ago D.later有什么 区别?

A.after B.before C.ago D.later有什么 区别? after before in ago later时态区别 after before in ago later区别时态 She got a herdache one week __.A;before B:ago C:later D:at He was a famous tennis player ( ) A ago B before C after D t before,ago,after,later用法上的区别 in later after ago before 的区分 twenty-one years ago和twenty-one later/after有什么区别 意思上呢 Have you met Mr Li____?A:just B:ago C:before D:a moment ago have you met Mr.Li A just B ago C before D a moment ago A) before B) while C) as D) after later,after,past有什么区别?