62. It worried her a bit　　　　 her hair turning grey.

A. while　　　　　 B. that　　　　 C. if　　　　 D. for

61. 　　　　　　We’ll go camping tomorrow depends on the weather.

A. If　　　　　　 B. Whether　　 C. That　　　 D. Where

60. It’s uncertain 　　　　the experiment is worth doing.

A. if　　　　　 B. that　　　 C. whether　　　 D. how

59. It was possible, but not probable　　　　 manager of the firm.

A. he will be elected　　　　　　 B. he must be elected

C.that he would be elected　　　 D. that he must be elected

58. 　　　　　Leaves the room last ought to turn off the light.

A. Anyone　　 B. The person　　 C. Whoever　 D. Who

57. The man asked 　　　　.

A. what was going on there　　　 B. what it was going on there

C. what’s going on there　　　　 D. what going on there

56. The reason why he hasn’t come is　　　 .

A. because his mother is ill　　　　 B. because of his mother’s being ill

C. that his mother is ill　　　　　　 D. for his mother is ill

55. China is becoming stronger and stronger.　 It is no longer　　　 .

A. what is used to be　　　　　　 B. what it was used to being

C. what it used to being　　　　　 D. what it was used to be

54. 　　　　　Mathematics is the base of all other sciences.

A. This is because B. This is that　　 C. It is that　　　　 D. Because

53. The reason he has been such a success　　　 he never gives up.

A. is because　　 B. is what　　　 C. is that　　　　　 D. is