1.---Did you hear me come in last night?
1.---Did you hear me come in last night?
---No,I _________ asleep.用情态动词回答
2.Mr Li doesn't have any gray hair,he ______ (be) very old.
3.castle in the middle ages _______(be) cold places.
4.Poor people five hundred years ago ______(have) easy live
7 he________(escape) by this window because it's locked.
题目要求是用can/ must /may/ can't be doing or can/could/may/might/must/should/need(not) have done来回答
不是很懂的请不要回答了 答了要讲理由的 我会追加50分的
1245楼的朋友们这样一只半解的人就不要来答了
1. must have slept,must have done,表示对过去的事情带有肯定语气的推断（根据有“没有听见对方来”这个事实）.
2. can't be 表示不可能.表示推断的否定语气用can't,不能用mustn't
3. 这道题我觉得有不止一个答案,因为没有上下文,用might/must haven been都可以表示推断,不严格的口语中,could be和might be也未尝不可.
4. couldn't have.这里的can表示“能力”,couldn't表示“不能够”.
5. can't have escaped,对过去的推断的否定,表示他不肯能是从窗户逃出去的,因为窗户锁着.当然,如果表示能力的话,也可以用can’t,表示他现在逃不出去,因为窗户锁了.
如果不懂的话再问吧,情态动词的功能确实很麻烦.