四川成人本科学位英语试题精讲：时态(4)

A. had been on B. was on C. has been on D. would be on
【答案】A for five minutes是延续性时间状语，句子时态应用完成时；when 引导的时间状语从句为过去式，主句时态应与之对应，所以应该用过去完成时。
15. All the apparatus______ before the experiment began.
A. have been tested B. had been tested C. were tested D. had tested
【答案】B。所有的设备都在实验开始前被测试过了。“test”是在过去的某个时间（began）之前发生的，即过去的过去，因此选择完成时。
16. I ___ writing the article by the time you get back.
A. shall finish B. must have finished C. have finished D. shall have finished
【答案】：D。本句为将来完成时。表示在将来的某一时刻或将来的某一时刻之前已完成，这一动作可以继续下去。When you come again in July we shall have moved into a new house.七月份你们再来的时候，我们就搬进新房子里去了。I shall have done it by the end of this week.我要在周末做完它。本句的意思是“我要在你回来之前写完这篇文章”。
17. Mrs. White became a teacher in 1985. She _____ for twenty years by next summer.
A. will teach B. would have taught C. has been teaching D. will have been teaching
【答案】D此题考查的是动词辨析。A 建议，但无suggest sb to do 这种用法；B 吸引；C 引诱，D劝说。根据题意应该是：Alice很相信你，只有你能劝说她放弃这种愚蠢的念头。故选D
18. In another year or so, you _____ all about it.