下列各组词语中没有错别字的一项（） A．笙萧阙疑陨命未雨绸缪 B．漫溯阑珊瞋目宵

已知函数f（x）=2-|x|，无穷数列{a_n}满足a_n+1=f（a_n），n∈N^*

（1）若a₁=0，求a₂，a₃，a₄；

（2）若a₁＞0，且a₁，a₂，a₃成等比数列，求a₁的值

（3）是否存在a₁，使得a₁，a₂，…，a_n，…成等差数列？若存在，求出所有这样的a₁，若不存在，说明理由．

如图所示，在坐标原点O处，能向四周均匀发射速度大小相等、方向都平行于纸面的带正电粒子。在O点右侧有一半径为R的圆形薄板，薄板中心O′位于x轴上，且与x轴垂直放置，薄板的两端M、N与原点O正好构成等腰直角三角形。已知带电粒子的质量为m，带电量为q，速率为v，重力不计。

（1）要使y轴右侧所有运动的粒子都能打到薄板MN上，可在y轴右侧加一平行于x轴的匀强电场，则场强的最小值E₀为多大？在电场强度为E₀时，打到板上的粒子动能为多大?

（2）要使薄板右侧的MN连线上都有粒子打到，可在整个空间加一方向垂直纸面向里的匀强磁场，则磁场的磁感应强度不能超过多少（用m、v、q、R表示）?若满足此条件，从O点发射出的所有带电粒子中有几分之几能打在板的左边?

— May I smoke here?

— If you ________, choose a seat in the smoking section.

A. should  

B. could

C. must  

D. may

阅读理解

     We know, painkillers in a tablet can make your headache go away, and antibiotic from a tube can

prevent your cuts from becoming infected. Can medicine come in chicken eggs? A team of scientists

from Scotland says "yes." They've kept some special chickens that lay eggs with disease-treating drugs

inside.

     These drugs are made of molecules called proteins. Animals make thousands of proteins-they're the

main ingredients(成分) in skin, hair, milk, and meat. Since animals can make proteins easily, they're

good animals for making protein drugs.

     Researchers have already made cows, sheep, and goats that pump out protein drugs in their milk.

But chickens are cheaper to take care of, need less room, and grow faster than these other animals.

"Those qualities could make chickens a better choice to become living drug factories." says Simon

Lillico of the Roslin Institute near Edinburgh, Scotland.

     Lillico and a team of researchers changed chickens' DNA-the code that tells cells how to make

proteins-so that the birds' cells made two protein drugs. One drug can treat skin cancer, and the other

treats a nerve disease called multiple sclerosis.

     The scientists changed the chickens' DNA so that the birds made these drugs only in their egg whites.

This protects the chickens' bodies from the drugs' possible harmful effects and makes it easy for scientists

to collect the drugs.

     These special chickens can pass on their drug-laying abilities to their chicks. So far, the Scottish

researchers have kept five generations of drug-producing chickens. But the scientists need to improve

these chickens. The chickens don't make enough drugs to treat people yet. Once the researchers perfect

their technique, you might eventually take your medicine from chicken eggs.

1. What is the best title of the passage?

A. Animals and Protein Drugs.

B. Medicine Packaged in Various Forms.

C. A Scotland Scientist and His Chickens.

D.Chickens: a Better Choice of Living Drug Factories.

2. Which of the following is Not True according to the passage?

A. It takes much shorter time for chickens to grow than cows, sheep and goats.

B. Compared to cows, sheep and goats, chickens are less expensive to be raised.

C. Chickens can produce the best quality of drugs among the drug-producing animals.

D. Chickens are smaller in size than cows, sheep and goats and therefore need less room.

3. Why did the chickens make the drugs only in the egg whites?

A. Because it will help to collect the drugs easily.

B. Because it will not change the DNA of the chickens.

C. Because it will be easy for the patients to take the drugs.

D. Because it will prevent possible harmful effects on the patients.

4. What can be inferred from the passage?

A.Scottish researchers have kept five more drug-producing chickens.

B.This technique still needs improving so as to satisfy the normal application.

C.In the future people with diseases will take eggs instead of pills.

D.  The chicks need to be improved so as to carry the same ability as their parents.

在人身意外伤害保险实务中，对于被保险人由于核爆炸、核辐射或核污染而可能受到的“意外伤害”，通常被列为（　）。

A．不可保意外伤害

B．一般可保意外伤害

C．普通可保意外伤害

D．特约可保意外伤害