7. _________in the IT company, David decided to say goodbye and start his own business.

　　　 A. Having ignored　 　　　　　　　　　　　　 B. To be ignored　 　　

C. Ignored　 　　　　　　　　　　　　　　　　　　 D. Ignoring

6. I think it’ll take at least another two months _______ the shopping center is completed.

A. until　 　　　　　　 B. before　 　　　　　 C. when　 　　　　　　 D. as

5. A child who lives in an uninteresting environment will develop less intelligence than ______ who lives in a rich and changing environment.

A. the one　 　　　　 B. one　 　　　　　　 C. those　 　　　　　 D. that

4. Ted ______ for two months in London last year to receive his yearly training.

A. stayed　 　　　 B. has stayed　 　 C. had stayed　 　 D. would stay

3. Standing on the top of the Oriental Pearl Tower, you will get a wonderful _______ of Shanghai city.

A. sight　 　　　　　　 B. scene　 　　　　　 C. scenery　 　　　　　　 D. view

2. --- It’s reported that over 100,000 people lost their lives in Haiti earthquake on January 12^th.

--- Yes, _______ news came as _______ shock to me.

A. the; a　 　　　　　 B. the; 不填　 　　　 C. a; a　 　　　　　　　　　　 D. a; the

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、D四个选项中，选出可以填入空白处的最佳选项。

例: It is generally considered unwise to give a child _______ he or she wants.

A. however　 　　　　　　 B. whatever　 　　 C. whichever　 　 D. whenever

答案是B。

1. --- Could I borrow your English dictionary?

--- _______. It’s on the bookshelf.

　 　　 A. With pleasure　 B. Help yourself　 C. Never mind　 　　 D. Not at all

22．(本小题满分14分)

对于正整数，用表示的最大奇因数，如：，……. 记，其中是正整数.

(I)写出，，，并归纳猜想与N)的关系式；

(II)证明(I)的结论；

(Ⅲ)求的表达式.

21．(本小题满分12分)

已知点， 是平面内一动点，直线、斜率之积为.

(Ⅰ)求动点的轨迹的方程；

(Ⅱ)过点作直线与轨迹交于两点，线段的中点为,求直线的斜率的取值范围.

20．(本小题满分12分)

如图1,在直角梯形中,,,, 为线段的中点.将沿折起,使平面平面,得到几何体,如图2所示.

(Ⅰ)　 求证:平面；

(Ⅱ)　 求二面角的余弦值.