设n阶方程A=(α1，α2，…，αn)，B=(β1，β2，…，βn)，AB=(γ1，

如图所示的四块玻璃制成的透镜中，对透过的光线有会聚作用的透镜是______，对透过的光线有发散作用的透镜是______（写字母）．

2010年诺贝尔物理学奖授予英国曼彻斯特大学科学家安德烈海姆和康斯坦丁诺沃肖洛夫，以表彰他们在石墨烯材料方面的卓越研究．石墨烯是目前世界上已知的强度最高的材料，它的发现使“太空电梯”缆线的制造成为可能，人类将有望通过“太空电梯”进入太空．现假设有一“太空电梯”悬在赤道上空某处，相对地球静止，如图所示，那么关于“太空电梯”，下列说法正确的是

A．“太空电梯”各点均处于完全失重状态

B．“太空电梯”各点运行周期随高度增大而增大

C．“太空电梯”上各点线速度与该点离地球球心距离的开方成反比

D．“太空电梯”上各点线速度与该点离地球球心距离成正比

驾驶机动车在拥堵的路口遇到这种情况怎样处置（）

A．逼其回原车道

B．紧跟前车不让行

C．礼让通行

D．鸣喇叭开前照灯

In America there are no nobles or men of letters, and the common folk mistrust the wealthy. Consequently, (1) form the highest political class, and the most cultivated circle of society. They have therefore (2) by innovation, which adds a conservative interest to their natural taste for (3) . If I were asked where I place the American aristocracy, I should reply (4) that it is not composed of the rich, who are united together by (5) , but that it occupies the judicial bench and the bar.
When I started researching this topic, I found an interesting (6) Legal Reform Now. As the name suggests, this web site is devoted to (7) , and it is definitely concerned about the dominance of lawyers in (8) . There I read an article by a (9) from the University of Wisconsin. One observation the UW article (10) is that the legal profession is the dominant profession of the people (11) to public office. For example, about half our representatives and (12) of our senators are lawyers. No other profession (13) having the same number of people in political office.
Effectively, lawyers form our nation’s (14) organized political constituency in America. Lawyers (15) and lawyers interpret our laws. When judges are appointed, the American Bar Association is the only (16) that is consulted to rate the fitness of potential judicial appointees.
Our nation has been in existence for (17) and lawyers have been this nation’s aristocracy since its (18) . Our system works, but do we really want to have a single profession (19) our nation. Specifically, do we want to have the legal profession in charge (20) , that is something to think about.

In America there are no nobles or men of letters, and the common folk mistrust the wealthy. Consequently, (1) form the highest political class, and the most cultivated circle of society. They have therefore (2) by innovation, which adds a conservative interest to their natural taste for (3) . If I were asked where I place the American aristocracy, I should reply (4) that it is not composed of the rich, who are united together by (5) , but that it occupies the judicial bench and the bar.
When I started researching this topic, I found an interesting (6) Legal Reform Now. As the name suggests, this web site is devoted to (7) , and it is definitely concerned about the dominance of lawyers in (8) . There I read an article by a (9) from the University of Wisconsin. One observation the UW article (10) is that the legal profession is the dominant profession of the people (11) to public office. For example, about half our representatives and (12) of our senators are lawyers. No other profession (13) having the same number of people in political office.
Effectively, lawyers form our nation’s (14) organized political constituency in America. Lawyers (15) and lawyers interpret our laws. When judges are appointed, the American Bar Association is the only (16) that is consulted to rate the fitness of potential judicial appointees.
Our nation has been in existence for (17) and lawyers have been this nation’s aristocracy since its (18) . Our system works, but do we really want to have a single profession (19) our nation. Specifically, do we want to have the legal profession in charge (20) , that is something to think about.

为防止四环素牙的发生，除妊娠和哺乳期的妇女外，几岁以下的小儿也不宜使用四环素

A．5岁

B．6岁

C．7岁

D．8岁

E．9岁