2. 解析：选A。考查代词的用法。A、B、C三项均可作不定代词：either指二者中任何一个；each指两者或两者以上中的每个人或每个物；one用来代替上文出现过的单数可数名词，泛指一个；D项it用作人称代词时，用来指代上文提过的某个事物。前句叙述了有咖啡和茶,根据常理，只能是二者之中选一种，故答案为A。

1. 解析：选D。would have done表示对过去已发生的事情的推测，表示“可能……”，故最佳答案是D项。

10. The students who do best in the examination are not always 　　　with the best brains.

A. the ones　 B. these　 C. them　 D. that

9. -Why did you stop writing?

-My ink has　　　 .

A. used up　　　 B. run out of

C. given away　 D. given out

8. I 　　　all my homework by the time you 　　　back.

A. will have finished; come

B. will finish; come　

C. will have finished; came

D. have finished; will come　

7. -How could I thank you enough?

-Don’t mention it. Any other man 　　　that.

A. must do　　　　　　 B. could do

C. would have done　　 D. should have done

6. When he was still a child,he　　 in the river, but now he no longer swims in it.

A. was used to swimming　　 B. used to swim

C. was used to swim　　　　 D. used to swimming

5. -I drove to Zhuhai for the air show last week.

-Is that the reason 　　　you had a few days off?

A. why　　 B. When　　 C. what　 D. where