51____ is well known, light, like heat, is a form of energy.

A. It B. what C. Just as D. As

52. You should turn off all the water tonight ____ freezes and the pipes burst.

A. in some cases it B. in case it C. in that case it D. in any case it

53. Music often____ us of events in the past.

A. reminds B. memorizes C. remembers D. reflects

54. He didn't know I was in his office. He was too busy to____ me.

A. pay attention to B. notice C. know D. realize

55. Does it____ much to have the bicycle repaired?

A. pay B. spend C. cost D. ask

56. You should act _____ the advice of your doctor.

A. to B. on C. at D. as

57. There was a teapot fashioned like a China duck, out of ____ open mouth the tea was supposed to ***e

A. which B. its C. that D. whose

58. Beijing is now busy___ the Olympic Games which is to be held in the year 2000.

A. preparing for B. prepared for C. to prepare for D. prepare for

59. The scientist didn't mind ____and went on with his investigation.

A. laughing at B. to be laughed at

C. being laughed at D. laughed at

60. If you____ that late movie last night, you wouldn't be so sleepy.

A. hadn't watched B. haven't watched

C. wouldn't have watched D. didn't watch

答案：

51-55 DBABC 56-60 BDACA