口腔颌面部肿瘤中上皮来源的占A．60％ B．70％ C．80％ D．50％ E．40

骑自行车的人以5m/s的初速度匀减速地骑上一个长30m的斜坡，加速度大小是0.4m/s2 。问：

小题1:骑自行车的人骑上斜坡要用多长时间？

小题2:自行车到达斜坡顶时的速度大小为多少？

下列文字表述错误的是[ ]

A．公民的权利与义务是相互依存、密不可分的

B．公民的权利与义务是相辅相成、互相转化的

C．权利与义务在法律关系上是相对应而存在的

D．公民既是权利的享有者，也是义务的承担者

“学生表”中有“学号”、“姓名”、“性别”和“入学成绩”等字段。执行如下SQL命令后的结果是　　Select avg(入学成绩) From学生表Group by性别

A．计算并显示所有学生的平均入学成绩

B．计算并显示所有学生的性别和平均入学成绩

C．按性别顺序计算并显示所有学生的平均入学成绩

D．按性别分组计算并显示不同性别学生的平均入学成绩

阅读理解。

     I needed to buy a digital camera, one that was simply good at taking good snaps (快照), maybe

occasionally for magazines. Being the cautious type, I fancied a reliable brand. So I went on the net,

spent 15 minutes reading product reviews on good websites, wrote down the names of three top

recommendations and headed for my nearest big friendly camera store. There in the cupboard was

one of the cameras on my list. And it was on special offer. Oh joy. I pointed at it and asked an

assistant, "Can I have one of those?" He looked perturbed (不安). "Do you want to try it first?" he

said. It didn't quite sound like a question. "Do I need to?" I replied, "There is nothing wrong with it?"

This made him look a bit insulted and I started to feel bad. "No, no. But you should try it," he said

encouragingly. "Compare it with the others."

     I looked across at the others: shelves of similar cameras placed along the wall, offering a wide

range of slightly different prices and discounts, with each company selling a range of models based

around the same basic box. With so many models to choose from, it seemed that I would have to

spend hours weighing X against Y, always trying to take Z and possibly H into account at the same

time. But when I had finished, I would still have only the same two certainties that I had entered the

store with: first, soon after I carried my new camera out of the shop, it would be worth half what I

paid for it; and second, my wonderful camera would very quickly be replaced by a new model.

     But something in the human soul whispers that you can beat these traps by making the right choice,

the clever choice, the wise choice. In the end, I agreed to try the model I had chosen. The assistant

seemed a sincere man. So I let him take out of my chosen camera from cupboard, show how it took

excellent pictures of my fellow shoppers… and when he started to introduce the special features, I

interrupted to ask whether I needed to buy a carry-case and a memory card as well.

     Why do we think that new options (选择) still offer us anything new? Perhaps it is because they

offer an opportunity to avoid facing the fact that our real choices in this culture are far more limited

than we would like to imagine.

1. The shop assistant insisted that the writer should _____

A. try the camera to see if there was anything wrong with it.

B. compare the camera he had chosen with the others.

C. get more information about different companies.

D. trust him and stop asking questions.

2. What does the writer mean by "it would be worth half what I paid for it" (paragraph 2)?

A. He should get a 50% discount.

B. The price of the camera was unreasonably high.

C. The quality of the camera was not good.

D. The camera would soon fall in value.

3. The writer decided to try the model he had chosen because he _____

A. knew very little about it.

B. didn't trust the shop assistant.

C. wanted to make sure the one he chose would be the best.

D. had a special interest in taking pictures of his fellow shoppers.

4. I t can be inferred from the passage that in the writer's opinion, _____.

A. people waste too much money on cameras

B. cameras have become an important part of our daily life

C. we don't actually need so many choices when buying a product

D. famous companies care more about profit than quality

含硫氨基酸是（）

A.亮氨酸

B.苯丙氨酸

C.蛋氨酸

D.甘氨酸

E.精氨酸