49.He wrote a letter to me 　that his trip to Japan had been put off because of the bad weather　

　 A. inform 　　 　　　 B. informing 　　 C. informed 　　　　 D. being informed

48.　 　a satisfactory operation, the doctor believed the patient would recover from his illness very soon.　

　 A. Having been given　　 B. Having given 　　　 C. Giving 　　　　　 D. Being given

47. 　　　　　 a satisfactory operation, the patient recovered from illness very quickly.　

　 A. Having been given　　 B. Having given 　　　 C. Giving 　 　 D. Being given

46. When I came in, I saw Dr. Li　　　　　 　a patient.　

　 A. examine　　 　　　 B. examining　　 　 C. to examine　　 D. examined

45. The cars 　　　in Beijing are as good as those 　　　in Shanghai.　

　 A. produce, produce 　 　 B. produced, produced

　 C. produced, producing　 　 D. producing, producing

44. The graduating students are busy 　　　　material for their reports.

　 A. collect　　 　 B. to collect　　 　　 C. collected　　 　　 D. collecting

43. I had to shout to make myself 　　　　above the noise.　

　 A. heared　　 　 B. hearing　　 　　　 C. heard　　 　 D. to hear

42. He walked down the hills, 　　　　softly to himself.　

　 A. sing　　 　　　 B. singing　　 　　　 C. sung　　 　　 D. to sing

41. At this moment the bell rang 　　　　　the end of class.　

　 A. announce　　 　　 B. announcing　　 　　　 C. announced　　 D. to announce

40. The child sat in the dentist's chair 　　　　.　

　 A. tremble　　 　　　 B. trembling　　 　 C. trembled　　 　　 D. to trembled