1. ---Excuse me, sir, is this seat taken?

---_______.

A. Sure, you may take it　 B. Certainly. Help yourself

C. No. I don’t think so　　 D. No. I don’t hope so

49. It is a long d________ from New York to Hongkong. 50. The river is about 20 feet b________. 　　　　　　　　　　　　　　　　

48. The country’s w________ comes from its oil.

47. Since 1965, the m________ leaf has been the centerpiece of the National Flag of Canada

46. Premier Wen Jiabao is paying an o________ visit to Japan.

45. The cost was f________ out at $ 530.

44. You must go through customs in order to pass across the b________.

43. The s________ here are quiet.

42. Though it was an e________ difficult task, they finished it in time.

41. There are 5 to 7 c________ in the world, depending on how you count them.