52. By pure chance he found the rare book he needed in a little shop.

51. Many newspapers reflect the opinions of the children.

50. They suddenly became aware of people looking at them.

49. Please sit where you like.

48. We are likely to finish the task ahead of time. 或 It is possible that we can finish the task ahead of time.

47. He was suddenly aware of his shallow English.或 He was suddenly aware that his English was shallow.

46．I hope to go to medical college. In the meantime, I am going to study chemistry.

16---20 CAABB　 21---25 ADCCC　 26---30 BDACA　 31---35 BBADC

55． 深圳是中国南海岸的一座城市。

单元测试答案：