54.______ by a greater demand for vegetables, farmers have built more green houses.

　 A. Driven　　 B. Being driven　　　 C. To drive　　　 D. Having driven

53. he children talked so loudly at dinner table that I had to struggle ______.

52. －Can I smoke here?

－Yes. We had a great time ______　 there.

A. people smoking　　　　　 B. people smoke　　　　　　 C. to smoke　　　 D. smoking

51. You can't imagine what difficulty we had ______ home in the snowstorm.

A. walked　 　　　　B. walk　 　　　　C. to walk　 　　D. walking

50. The crowd cheered wildly at the sight of Liu Xiang, who was reported ______ the world record in the 110-meter hurdle race.

A. breaking　 　　　B. having broken 　C. to have broken 　　D. break

49. The Town Hall ______ in the 1800’s was the most distinguished building at that time.

　 A. to be completed　　　　　　　　　　　　　　　　　 B. having been completed

　 C. completed　　　　　　　　　　　　　　　　　　　　　 D. being completed

48. There is nothing more I can try ______ you to stay, so I wish you good luck.

　 A. being persuaded　　 persuading　　　　　　　 C. to be persuaded　　 D. to persuade

47. After a knock at the door, the child heard his mother’s voice ______ him.

　 A. calling　　　　　　　　　 B. called　　　　　　　　　 C. being called　　　　 D. to call

46. --- Did you tidy your room?

　 --- No, I was going to tidy my room but I ______ visitors.

　 A. had 　　　　　　　　　　 B. have　　　　　　　　　　 C. have had　　　　　　 D. will have

45. The glass doors have taken the place of the wooden ones at the entrance, ____ in the natural light during the day.

A. to let　　　　 B. letting　　　　　　 C. let　　　　　 D. having let