－What is he doing?

－He’s ________ to be cleaning his bedroom．

A．forced

B．known

C．supposed

D．regarded

________ surprised Mr．Smith most was that recently Tom had done his homework neatly and correctly．

A．It

B．That

C．What

D．Which

The two collectors have determined to buy the precious Egyptian vase, ________．

A．however much it costs

B．no matter how it costs

C．however much does it cost

D．no matter how much does it cost

－Bob, are you free at the moment? I have to ask you some questions．

－________．

A．It’s a pleasure

B．Ask, please

C．Help yourself

D．Yes, go ahead

We were looking for you all this morning．You ________ office without a word．

A．mustn’t leave

B．shouldn’t have left

C．couldn’t have left

D．needn’t leave

He wondered if he could slip out of the lecture hall without anyone ________．

A．noticing

B．notice

C．to notice

D．being noticed

I thought I was going to fail the driving test but I succeeded ________．

A．after all

B．first of all

C．in all

D．at all

Living in the country has its advantages, ________ freedom from pollution is the best．

A．which

B．whose

C．of which

D．from which

We need an in ________ strument, must be small．

A．which the size of

B．of which size

C．the size of which

D．which of the size

Could it be in the room ________ we had a talk last night ________ you left your key?

A．that; where

B．where; when

C．where; that

D．where; where