第三节 完形填空（共20小题；每小题1分，满分20分）
阅读下面短文，掌握其大意，然后从31-50各题所给的四个选项（A、B、C和D）中，选出最佳选项, 并在答题卷上将该项涂黑。
People often fall ill because of me. 31__, they can hardly blame me; it is largely their own 32 . A tired person may get caught, 33 _ when he goes to crowded places with polluted air. A sudden change in 34 is another factor. In hot summer, people turn on the air-conditioner upon returning home. They will catch a cold easily.
My latest victim is an energetic student. After school, he played football hard for two hours. Though 35 , He still went to the cinema. Then he got back home and took a cold shower immediately. I 36 this golden chance to attack him. He reacted, trying to 37 me, but I was already 38 deep in his throat. He kept sneezing (打喷嚏) and his nose was running. 39 he put on some warm clothes, it didn't work, for there were too many of us. Besides, his sore throat kept 40 him, and he developed a cough to force me and my family out, but 41 .
The next day he couldn't go to 42 . He had lost his appetite and was not as 43 as before. His mother made him orange juice every few hours for more vitamin C, which would help his 44 .
For two days he was 45 by his mother. As he rested more, his defense strengthened and I began lo feel the 46 . I knew I had to 47 him before long. But I am not the one who gives up easily, and I 48__ every effort to fight back. 49 , it was my turn to feel painful now, for his defense system was starting an all-out attack against me. I became 50 and finally my time was over.
Do you know what I am?
31. A. Therefore B. Besides C. However D. Then
32. A. business B. responsibility C. excuse D. fault
33. A. especially B. specially C. certainly D. finally
34. A. temperature B. season C. place D. condition
35. A. excited B. hurt C. late D. tired
36. A. held B. felt C. seized D. lost
37. A. get on with B. get rid of C. put up with D. take hold of
38. A. multiplying B. waiting C. hiding D. disappearing
39. A. Since B. Once C. Whether D. Although
40. A. reminding B. upsetting C. comforting D. influencing
41. A. escaped B. succeeded C. regretted D. Failed
42. A. bed B. work C. school D. hospital
43. A. peaceful B. afraid C. active D. careful
44. A. recovery B. development C. study D. growth
45. A. protected B. nursed C. scolded D. affected
46. A. loss B. operation C. pressure D. movement
47. A. leave B. catch C. forget D. beat
48. A. took B. made C. had D. put
49. A. Uncertainly B. Unsuccessfully C. Unusually D. Unfortunately
50. A. bigger B. weaker C. smaller D. stronger