7.The water isn't fit ________ .

A. drinking　　 B. drunk  C. to drink　　  D. to be drunk

6.This small country is known ________ rich in natural resources.

A. being  B. to be    C. for being　　   D. to being

3.I would appreciate ________ back this afternoon.

A. you to call    B. you call

C. your calling　　     D. you're calling

2.Did ________ on time make her teacher angry?

A. not to come　　   B. her not to come

C. her not coming  D. not her coming

1.Before ________ , we must check the machines.

A. using them   B. having used　　   C. use them　　   D. being used

59.We got home to find the whole house ______ upside down. Thieves obviously _____.

A. turned; had broken in　　　　　　  B. turned; had broken into

C. to have turned; had been broken in   D. turning; had been broken into

56. A  We should keep ourselves ________ of the changing situation.

54.—Shall we go swimming?

—OK, I'll just go and ________ .

53.Slowly she opened the letter, ________ .

51.It was clever ________ at the decision in two minutes.