27. Do you really want to borrow the old room which is empty _____a broken desk and a chair?　

A. except　 B. except for　　 C. except that　　 D. besides 　

26. Just because they make more money than I do,　 _____ they seem to look down on me.　

A. so　　 B. and　　 C. but　　 D. 不填 　

25. It is going to rain today.Take an umbrella with you to　 _____ you from the rain.　

A. stop　 B. prevent　 C. keep　 D. protect 　

24. My friend, Lucy ,can get 200 dollars more than she made _____in the primary school.　A.work　 B.to work　 C.working　 D.worked 　

23. _____ is hard is to do good all one's life and never do anything bad.　

A. He　 B. It　 C. That　 D. What 　

22.-I've never found a better job and I’m so glad.　

- _____.　

A. I don’t think so　　 B. Too bad　

C. Congratulations　　 D. Don’t worry 　

第一节 单项填空(共15小题；每小题1分，满分15分)　

从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。

21.-Have you seen _____ pen? I left it here this morning.　

-Is it _____ black one? I think I saw it somewhere.　

A. a, the　　　 B. the, the　　　 C. a, a　　　　 D. the, a 　

20．(本小题共14分)

　　　 数列的前n项和为，点在直线

上.

　 (I)求证：数列是等差数列；

　 (II)若数列满足，求数列的前n项和

　 (III)设，求证：