11. “Are Alice and Tom still living in New York?” “No, they _____ to Dallas.”
A. are just moved B. have just moved C. had just moved D. will just move

12. I haven't heard from Maria_____.
A. since a long time    B. for many months ago
C. for many months    D. since many months before

13. His grandfather ______ for thirty years.
A. died B. was dead C. has been dead D. has died

14. Its (high) time you _____ a holiday.
A. had B. have C. will have D. have had

15. By the time Juan gets home, his aunt _____ for Puerto Rico.
A. will leave B. leaves C. will have left D. left

16. All the machines ____ by the end of the following week.
A. were repaired       B. will be repaired
C. have been repaired      D will have been repaired

17. The conference _____ a full week by the time it ends.
A. must have lasted B. will have lasted C. would last D. has lasted

11. B 现在完成时态。说话的时候,他已搬走。
12. C 我已经好几个月没有 Maria 的消息了。现在完成时态, for 引导一个时间状语。
13. C 现在完成时态。他的祖父已经去世三十年了。这里死亡表示一种状态,而不能理解为一种动作,因为死亡是一个短暂性动词,它不可能持续三十年。所以用 has been dead 。
14. A It's(high)time (是 …… 什么的时候了)的特殊用法,要用完成时态。 Have 在句中是拥有的意思。
15.C 将来完成时态。 Leave for 离开一个地方到另一个地方去, By the time  信号词。
16.D 将来完成时态。 by the end of  到 …… 时间为止,在此句中引导的时间状语从句为将来时间,所以是用将来时。答案 B , D 选取哪个?机器( machines )是被修的,所以用被动语态。显然, D 为正确答案。
17. B 译文:会议从开始到结束,将持续整整一个星期。本句是将来完成时的用法。到将来某时(会议结束)之前业已完成的动作(last) ,所以用将来完成时。