分类：教育/科学-外语学习-英语考试
问题：还有些问题，是单选题21、—Where______themusi 
21、— Where______the  album? I can’t see it anywhere. — I_______it right here. But now it’s gone! A.did you put / have put B.have you put / put C.had you put / was putting D.were you putting / have put  22、Great changes_______since New China_______. A.have been taken 21、— Where______the  album? I can’t see it anywhere. — I_______it right here. But now it’s gone! A.did you put / have put B.have you put / put C.had you put / was putting D.were you putting / have put  22、Great changes_______since New China_______. A.have been taken place / founded  e taken place / is founded C.have taken place / was founded D.were taken place / has founded  23、Tell the children not to watch TV until they _____ their homework.  nishes B.will finish C.have finished  nished  24、How we miss him! He _______here for months. A.has been away from B.left C.has left D.has been off  25、My sister_______a teacher for about six years. A.has become B.has turned C.has changed D.has been  
回答：21 B 第一句不知道具体发生的时间，第二句实指过去
22 C since出现主句用现在完成时，但是新中国成立是过去时。
23 C 表示时间截止
24 A for表示动作延续
25 D been可以表动作延续，其他不行