21.Japan is ________ the east of China. Taiwan is ____ the southeast of China.

　　A. in; in

　　B. to; in

　　C. on ; to

　　D. in; to

　　解析：选B. 日本位于中国东部(外面)用to, 台湾位于中国东部(内部)用in。

　　22.The postman shouted, “ Mr Green, here is a letter ________ you.”

　　A. to

　　B. from

　　C. for

　　D. of

　　解析：选C. 介词的考查。句意：Mr Green, 这是你的信。学生容易误选A。

　　23.He hasn’t heard from his friend __________ last month.

　　A. since

　　B. by the end of

　　C. for

　　D. until

　　解析： A. 此题学生容易受思维定势not… until…的影响误选D。since用于现在完成时，如果此题是一般过去时就选择D。

　　24.—Jimmy lost his key yesterday.

　　—________? It’s his third time in just one month.

　　A. Has he

　　B. Did he

　　C. Was he

　　D. Does he

　　解析：B. 根据上一句一般过去时可以判断。

　　25.You’ve passed the exam. I’m happy ______ you.

　　A. on

　　B. at

　　C. in

　　D. for

　　解析：选D. 句意：你考试及格了，我为你高兴。

　　26. I wonder ________ they finished so many different jobs in such a short time.

　　A. why

　　B. how

　　C. when

　　D. where

　　解析：选B. 句意：我想知道他在如此短的时间内是怎样完成这么多不同工作的。

　　27. —Ought I to go right now?

　　—_________.

　　A. That’s very bad.

　　B. Yes, you go ought to

　　C. Yes, you ought

　　D. No, you ought not to

　　解析：选D. 句子的肯定回答为：Yes, you ought to. 否定回答为：No, you ought not to.

　　28. I don’t know when he ________. When he _______ here, I’ll call you in a minute.

　　A. will come; will arrive

　　B. comes; arrices

　　C. will come; arrives

　　D. comes; will arrive

　　解析：选C. 第一句是宾语从句根据语境用一般将来时，第二句是时间状语从句，由于主句是一般将来时，那么从句要用一般现在时来代替。

　　29. He turned ________ the radio a little because his father was asleep.

　　A. on

　　B. down

　　C. up

　　D. off

　　解析：选B. 此题学生会误选D. 但后面有个副词短语a little, 故选择B, 意为：把收音机调小一点，父亲在睡觉。如果去掉a little则选择D。

　　30. I don’t know the homework _______ today.

　　A. on

　　B. in

　　C. of

　　D. for

　　解析：选D. 句意： 我不知道今天的家庭作业。