9. You must try some of her home-made wine. It’s quite an unforgettable ________.

　 A. entertainment　　 B. experience　　 C. adventure　　 D. addiction

8. ________ to our help when we were in trouble, we couldn’t have finished our task on time.

　 A. If she didn’t come　　　　 B. If she wouldn’t come

　 C. Had she not come　　　　 D. Would she not come

7. Premier Wen’s three-day visit to Japan, ________ as the “ice-melt” trip, had a positive effect on Sino-Japanese relationship.

　 A. being intended　　　　 B. intended　　

　C. having intended　　　　 D. intending

6. ________ their aim may seem good, they probably do not realize that dieting can do harm to their health.

　 A. If　　　　 B. Because　　　　 C. While　　　　 D. When

5. In a sports team each player has a clear role, and there are few occasions ________ members are confused or uncertain of their roles.

　 A. when 　　　　B. whose　　　　 C. why　　　　 D. which

4. When I took his temperature, I found it was two degrees ________ average. He got a fever.

　 A. above　　　　 B. over　　　　 C. on　　　　 D. below

3. It’s terrible that the car ________ break down just as we were going on our holidays.

　 A. could　　　　 B. would　　　　 C. might 　　　　D. should

2. Wherever we go, we find that in no city of China ________ little about the economic development.

　 A. the government cares　　　　　 B. does the government care

　 C. doesn’t the government care　　　 D. the government doesn’t care

第一节：单项填空(共20小题；每小题0.5分，满分10分)

从A、B、C和D四个选项中，选出可以填入空白处的最佳选项，并在答题纸上将该选项标号涂黑。

1. - Do you think I should join the singing group, Anna?

- ________ If I were in your shoes, I certainly would.

　 A. None of my business.　　　　 B. It depends.

　 C. Why not?　　　　　　　　　 D. I don’t think so.

22．(本题满分15分)

已知数列{}中，在直线y=x上，其中n=1,2,3….

(Ⅰ)令 (Ⅱ)求数列

(Ⅲ)设的前n项和,是否存在实数，使得数列为等差数列？若存在，试求出.若不存在,则说明理由。