1.it must have rained last night,for the ground is wet.
2.the lights were out,so they must have been out.
3.he can’t have forgotten it,for he talked about it yesterday.
4.can he have gone to his aunts?
5.you could have done better,but you didn’t try your best.
6.I saw Mr.smith just now,he couldn’t have gone back to America.
7.it’s too late,I think he have gone to bed.
8.he might have caught a cold.
9.he may not have finished his work.
10.you might have given him more help,though you were busy.
11.you should have come to the meeting earlier.
12.you ought to have done the job more carefully.
13.he ought not to have treated his parents like that.
14.you needn’t have taken a taxi here,for it was so near to my house.
15.I didn’t need to cook the dinner,because my mother has done it.
请帮忙翻译一下、谢谢。
参考资料:翻译工具
参考资料:有道桌面词典