1.He was busily engaged ______ writing letters.

　　A. on 　B. in 　C. with 　D. by

　　2.Do remember to ______ the light when you leave the room.

　　A. turn up 　B. turn on 　C. turn off 　D. turn down

　　3.The atmosphere consists of an ocean of gases ______ miles high.

　　A. hundreds 　B. hundreds of 　C. of hundreds 　D. of hundreds of

　　4.Not only the students but also the old teacher ______ been changed.

　　A. was 　B. were 　C. has 　D. have

　　5.—— ________ I had!

　　—— You really suffered a lot.

　　A. What a time 　B. What time 　C. How a time 　D. how time

　　答案：

　　1.正确答案：B答案解析：be engaged in：从事，忙于。

　　2.正确答案：C答案解析：根据句意，应该选择“关闭”。句意：离开房间时一定记着把灯关掉。

　　3.正确答案：B答案解析：译文：大气由上百英里高的气体组成。“hundred，thousand等数词的复数形式+of短语”表示的是不确切的数量。

　　4.正确答案：C答案解析：not only…but also…是固定搭配，意思是：不但……而且……。它需要遵循就近原则，谓语动词应与the old teacher一致，所以答案是C.

　　5.正确答案：A答案解析：感叹句分两类：

　　1：What + n.+主谓部分2：How + adj. / adv. / v.+主谓部分。本题属第一种，但省略了bad，相当于 What a bad time I had! 这是个习惯用语。