48. The Changjiang River is the third longest river in the world. So far many b have been built over it.

47. Tom was late for class yesterday. When he came into the class,all of us were d the questions.

46. —What's your favourite season?

—I like s best. It's a good time to have a swim in hot weather.

45. 一Does your father a  with you,Jeff?

一Yes. He thinks to be a volunteer in Children^ Hospital is a good job.

44. —Would you like some tea or coffee?

—E  is OK. I don't mind.

43. I wrote three letters to him,but he never r to any of them.

42. The pear is delicious. Can you give me a  one?

41. The girl often goes to school w having breakfast.

40. To live a green life,we should try to save more energy and produce less p .

39. What's your p about the future?