He ________ live in the country than in the city.

[　　]

Were the wire of a smaller diameter, its resistance ________ increased.

[　　]

I can't give you an answer before I ________ carefully.

[　　]

She got twenty pounds a month for ________ fifteen rooms.

[　　]

Everyone ________ the cake because there wasn't even a small piece left.

[　　]

Class will be over ________.

[　　]

I didn't hear the phone. I _____ asleep.

[　　]

A．must be　　　B．must have been

C．should be　　 D．should have been

Do you know the boy _____ in the tree?

[　　]

A．lay　　　　B．lying

C．laying　　　D．lain

_____ got into the room, _____ the telephone rang.

[　　]

A．He hardly had; then

B．Hardly had he; when

C．He had not; than

D．Not had he; when

We _____ for her because she never came.

[　　]

A．needn't wait

B．shouldn't have waited

C．mustn't wait

D．mustn't have done