手机短信验证
1．(1)can表示推测时常用于否定句和疑问句，语气很强烈。
Mr.Bush is on time for everything.How can it be that he was late for the meeting?
布什先生做什么事情都很准时，他怎么可能开会迟到呢？
(2)can用于肯定句中，常表示客观的可能性。
It is usually warm in my hometown in March，but it can_be_ rather_cold sometimes.
我的家乡在三月份通常很暖和，但有时候也会相当冷。
2．may用于肯定句中可以用来表示推测，意为“可能”；用于否定句中也可以表示推测，may not意为“可能不”，表示一种不太确定的语气。
The traffic is heavy these days.I might arrive a bit late，so could you save me a place?
这些天交通很繁忙，我可能会来晚一点，请你帮我保留个位置好吗？
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“情态动词＋have done”的用法
1．can/could have done表示“本来可以做，而实际上未做”或者“过去可能做过”，疑问或否定形式表示对过去发生的行为表示怀疑或不肯定，其中can't have done多用于语气强烈的否定，意为“不可能做过”。
Sorry，Cathy，I didn't know that you were badly short of money then.But you could have asked me for help.
对不起，Cathy，我不知道你当时急需用钱，但是你本可以向我求助。
2．may/might have done表示对过去行为的推测，意为“可能做过”。might所表示的可能性比较弱，语气较委婉。此外might have done可表示“本可能做而实际上未做”。
Sorry，I'm late.I might_have_turned_off the alarm clock and gone back to sleep again.
对不起，我迟到了。我可能把闹钟关掉后又睡着了。
3．must have done表示对过去行为的推测，意为“一定，想必”，语气十分肯定。
—Ye Shiwen was lucky to win two gold medals in London Olympic Games.
k——真幸运，叶诗文在伦敦奥运会上获得两枚金牌。
—She must_have_gone_through tough training.
——她肯定受过严格的训练。
4．should/ought to have done表示过去本来应该做某事而实际上却没有做；shouldn't/ought not to have done表示过去本来不应该做某事而实际上却做了。这一用法往往含有责备的意味。
I shouldn't_have_watched that movie—it'll give me horrible dreams.
我本不应该看那部电影——它会令我做噩梦。
5．needn't have done表示本来不必做某事而实际上却做了。
Mark needn't_have_hurried.After driving at top speed，he arrived half an hour early.
马克本没必要那么匆忙。他以最快速度开车，结果早到了半个小时。
用适当的情态动词填空
W: Adam，how is your knee today? Is it still giving you trouble?
M: No，it feels a lot better today.If I had not run too fast，I __1__ not have been injured.I went to the doctor and he told me it was not serious，but I __2__ not take any strong activity in a few days.
W: Great! But I advise you __3__ take it easy today.Maybe just practice throwing.You __4__ not do any running any more.
M: OK.__5__ I have any news about Michigan and what __6__ we expect in Saturday's game?
W: Yes，I have some films，showing Michigan in the last three games.They are in my office，if you __7__ see them after practice，you can.
M: Oh，that __8__ be great.I'd like to see what we are against.They are one of the top basketball teams in the country now since they beat Iowa last weekend.Come to think of it，why don't you go ahead and check out the game films right now? And just rest that knee this afternoon.I wish you __9__ recover soon.
W: Michigan has a strong team.We are in for a tough one.
M: All right，I __10__ be back tomorrow for full practice.
答案
1.would
2.should
3.should
4.need
5.May
6.can
7.must
8.would
9.would
10.will
