24. The MP4 my father bought me on my birthday isn’t missing; it still _____ where I _____ it several days ago.

23. Is it twenty years that it may be _____ his father drank last?

22. When her father fell into a serious disease, she would sit before the window with her eyes _____ at the street without thinking anything.

第一节：单项填空(共15小题；每小题1分，满分15分)

请从A, B, C, D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该选项的标号涂黑。

21. _____ is acknowledged to us is that Qian Xuesheng _____ great contributions to our country's agriculture.

22．(本题满分15分)

已知a为实数，函数，

(1)若a=1,求函数的极值；

(2)求函数在上的最小值；

21．(本题满分15分) 已知函数在R上是奇函数，且在处取得极值.

(Ⅰ)求函数的解析式及其单调区间；

(Ⅱ)若对任意的实数、，求证:。

20．(本题满分14分)已知递增的等比数列满足,且是的等差中项.

(Ⅰ)求数列的通项公式;

　(Ⅱ)若,是数列的前项和,求使成立的的最小值.