21．____ more clearly , they came up and got close to it.

A．Seeing

B．Seen

C．To see

D．To be seen

20．____ surprised me most was ____they had finished the work so quickly.

A．What; what

B．That; that

C．What; that

D．That; what

19．The school ____ I studied ten years ago is ____ we visited yesterday.

A．where; that

B．that; which

C．where; the one

D．which; that

18．----Why not ask your neighbors for help?

----____ . I hardly know them.

A．I'm afraid not

B．That's a good idea

C．You'd better not

D．That's right

17．----Is she an artist?

----No, she is ____ an artist ____a musician, a famous musician.

A．both; and

B．not; but

C．neither; nor

D．either; or

16．There are many different forms of ____that we can make use of, such as gas, oil winds, waves and so on.

A．energy

B．source

C．force

D．matter

15．Don't play with the burning stick, children. It often ____fire.

A．makes

B．catches

C．sets

D．causes

14．----That would mean ____much more money.

----Really? I don't mean ____any more money.

A．wasting; wasting

B．to waste; to waste

C．to waste ; wasting

D．wasting ; to waste

13．Dr. Bethune began to work ____he arrived at the front.

A．the moment

B．by the time

C．hardly when

D．at the moment

12．----Were all these people in the bus injured in the accident?

----No, ____only three passengers who got hurt.

A．it was

B．there was

C．they were

D．there had