(4)She needn't have come yesterday.她昨天本不必来的。

　　(5)It's late.He might have gone to bed.时间不早了,他也许已经睡觉了。

　　(6)You could have given more attention to it.你本可以多关心它一点的。

　　情态动词表示推测用法小结:

　　(1)should/ought to have done 　　　　　　　

　　(2)shouldn't/oughtn't to have done 　　　　　　　

　　(3)must have done 　　　　　　　

　　(4)can't/couldn't have done 　　　　　　　

　　(5)needn't have done 　　　　　　　

　　(6)might/may have done 　　　　　　　

　　(7)could/might have done 　　　　　　　

　　二、语法聚焦自测

　　1.用should,must,can,need,had better的相应形式填空

　　(1)You look tired.You 　　　　 go to bed now.

　　(2)-My mother cooked a lot of food for me.She has been cooking all the morning.

　　-She 　　　　 be tired now.

　　(3)-I have just eaten a lot of food for lunch.

　　-You 　　　　 be hungry now.

　　(4)The floor is clean.You 　　　　 sweep it.

　　(5)I can manage the shopping alone.You 　　　　 come with me.

　　(6)You 　　　　 not disturb him.

　　2.I searched for my wallet in the bag but it wasn't there.I thought I 　　　　 it at home.

　　A.left B.have left

　　C.might have left D.can have left

　　3.I 　　　　 asleep because it took me a long time to realize that the telephone was ringing.

　　A.could have fallen　　

　　B.should have fallen

　　C.must have fallen

　　D.mustn't have fallen

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挑战一　小试牛刀