14.He is ill.He___has been lying____(lie)in bed for 3 weeks.
---该句使用现在完成进行时比单纯使用现在完成时好，更能体现“躺”的持续性。
15.He___will have been___(be)in the United States for six years by the time he__graduates____-(graduate)from the university next year.
---该句根据后面时间状语next year，应该使用将来时，再看前面for six years,更有by...短语（多用完成时，表：到...（时间）为止）则表示到明年毕业就满6年（强调be的结果），故用将来完成时；后面是时间状语从句（by the time引导），根据主句将来时，从句一般现在时的原则，则后面动词第三人称单数，加-s;
16.I think he___wrote____(write)the novel at the age of 52.
---在52岁时写书，则具体时间，一般过去式。
17.Don't you remember that we____will\shall go _____(go)to the theater tonight?
---时间状语tonight 今晚，一般将来时，表示你记得要...吗？
第一人称I及We可用will也可用shall；
再则，如果开头是Didn't...那么后面就可能要用一般过去式或过去完成时，表示你不记得已经...了吗
18.This restaurant____will give_____(give)its customers a 10%off discount.It only lasts for 3 days.
---后面仅仅三天（一般现在时），则前面表示将要，一般将来时
19.We have to go to the seaside in his car because ours___is\are fixed____(fix).
----ours=our car(s),车（被）修理，被动语态；前面have to(一般现在时表示将来动作概念）后面单纯讲车坏要修，一般现在时的被动语态
20.I can see John is really angry.He___is shouting____(shout)at me.
---前面can see,现在发现，在朝我叫嚷，现在进行时
21.By 8 o'clock tomorrow,Betty___will have left___(leave)Macau.
---by,见上，多引导完成时态，明天8点前，就会离开澳门，将来完成时
另，如果完成时后面有for 介词短语或since短语\从句,那么leave就要变be away
22.I thanked him for what he___had done_____(do)for me.
---thank动词用一般过去时，在他前面的动作用过去完成时
23.By the end of last semester,we_____had learnt\learned_____(learn)more than3,000 words.
---by the end of last...-------过去完成时
24.A friend of mine__will come___(come)to see me tomorrow morning.
---tomorrow morning----一般将来时
25.I hate my neighbors!They____are always making_______(always/make)so much noise.It is absolutely annoying!
---该句用现在进行时比一般现在时更突出憎恨，总是（不停，不断，持续）
26.How come Bobby____is_____(be)quiet today?Is it sick?
----How come Bobby为什么这么个结构，看不懂；但后面还是可以判断是一般现在时
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