49. Wind power is an ancient source of energy 　　　　we may return in the near future.

A. on which　　　 B. by which　　　　　 C. to which 　　　　　 D. from which

48. ---More and more high-rise buildings have been built in big cities 　　　　　space.

　 ---I couldn’t agree more.

A. in search of　　 B. in place of　　　　 　 C. for lack of　　　 D. for fear of

47. I have seldom seen my mother ________ pleased with my progress as she is now.

A. So　　　　　　 B. very　　　　　 　　　 C. too　　　　　　 D. rather

46. Jack took the boxes off the little table to make _______ for the new computer.

A. area　　　　　 B. room　　　　　　 　C. field　　　　　 D. position

45. Though ______ to see us，the president gave us a warm welcome and showed us around.

A. surprise　　　　 B was surprised　　 　 C. surprised　　 D. being surprised

44. The settlement is home to nearly 1,000 people, _____ left their village homes for a better life in the city.

　 A. many of those　 B. many of which　　 C. many of them　　　 D. many of whom

43. ---Is everyone here?

---Not yet. Look, there_______ the rest of our students!

A. come　　　　　 B. comes　　　　　 C. is coming　　　 　　　　　 D. are coming

42. It was from only a few supplies that she had bought in the village 　　　　　the hostess cooked such a nice dinner.

A. where　　　　 　　 B. which　　　　 　　 C. when　　　　　　　 　 D. that

41. Every minute counts before the Entrance Examination. So we must ________the limited time.

　 A. make useful of　　 B. make the best of　　 C. take charge of　 D. take care of

40. -why, James, you look so tired!

　 ---Well, I _____the house and I must finish the work tomorrow.

A. was painting　　 B. will be painting　　 　　　 C. have painted　 D. have been painting