--What do you think of it?--I think it is a thing of importance that it ____ don

题型：不详难度：来源：

--What do you think of it?

--I think it is a thing of importance that it ____ done soon.

A．is

B．is to be

C．be

D．to be

答案

解析

can／could not +have done用于疑问句或否定句时，表示对过去情况的推测.表示不可能作过某事。

举一反三

Since the road is wet this morning, _____ last night.

A．it must rain

B．it must be raining

C．it must have rained

D．it must have been rain

题型：不详难度：| 查看答案

— Will your brother stay home tonight?
— I’m not quite sure. He _____ to the cinema tonight.

A．must go

B．can go

C．may go

D．may be going

题型：不详难度：| 查看答案

You must be a writer, _____?

A．mustn’t you

B．are you

C．must you

D．aren’t you

题型：不详难度：| 查看答案

I got up early that morning, but I _____ so because I had no work to do.

A．mustn’t have done

B．didn’t need to do

C．needn’t have done

D．can’t have done

题型：不详难度：| 查看答案

I missed the last bus, so I _____ go home on foot.

A．must

B．have to

C．may

D．had to

题型：不详难度：| 查看答案