-42+6425÷0．83+752×|(-215)2-225|．

如图所示，直角坐标系xOy位于竖直平面内，在水平的x轴下方存在匀强磁场和匀强电场，磁场的磁应强度为B，方向垂直xOy平面向里，电场线平行于y轴，一质量为m、电荷量为q的带正电的小球，从y轴上的A点水平向右抛出，经x轴上的M点进入电场和磁场，恰能做匀速圆周运动，从x轴上的N点第一次离开电场和磁场，M、N之间的距离为L，小球过M点时的速度方向与x轴的方向夹角为θ，不计空气阻力，重力加速度为g，求：

（1）电场强度E的大小和方向；

（2）小球从A点抛出时初速度v₀的大小；

（3）小球从A点运动到N点的时间t．

The 149th anniversary of Washington University’s founding will be celebrated with a presentation of Distinguished Alumni(校友) Awards for six famous teachers and alumni for their outstanding professional achievements, public service, extraordinary service to Washington University, or all three. Among the sixd awards winners for this year is Chen Zhangliang.

Chen Zhangliang is one of China’s most famous scientists, who was born into a poor fisherman’s family in Fuqing City, Fujian Province in 1961. after graduating from a university at home, Chen went to the US for further study. Since coming to Washington University as a doctoral student in 1983 to study transgenic(转基因的) plant engineering, Chen’s academic career has focused on gene cloning and the development of disease-and-pest-resistant plants. He completed his doctoral degree in biology at Washington University in 1987 and returned to Beijing to establish the National Laboratory of Plant Genetic Engineering at Peking University.

A productive scholar, Chen has published many books and more than one hundred research papers. He holds over ten patents with an equal number pending(等待决定的). Currently he is president of China Agricultural University and vice president of Peking University.

In addition to his academic career, Chen is also founder and president of the Weiming Biotechnology Company, which produces many DNA recombinant drugs and vaccines. He’s also a representative of China’s National People’s Congress and vice chairman of China Biotechnology Association. In addition, he serves as vice chairman for the China’s National Youth Federation.

Among his many honors are the UNESCO Javed Husain Prize for Young Scientists and TIME’s Global 100 Roster of Young Leaders for the New Millennium, as well as the Science and Technology prizes from the Ministry of Education in China.

41. Chen Zhangliang takes part in the following activities EXCEPT __________.

A. the Chinese government’s work

B. the university’s management

C. the management of agriculture

D. the production of biochemistry medicines

42. Which of the following is NOT true according to the passage?

A. Chen Zhangliang gained a doctor’s degree at the age of 26.

B. It’s possible for Chen Zhangliang to obtain about 20 patents.

C. Chen Zhangliang established the genetic engineering laboratory in Beijing.

D. Distinguished Alumni Awards are mainly given to the students of the university.

43. What’s the passage mainly about?

A. An introdction to Washington University’s anniversary activities.

B. A brief introduction to a world-famous university.

C. The scientific achievements and honors of Chen Zhangliang.

D. The career development of Chen Zhangliang

44. This passage gives us the inspiration that ___________.

A. knowledge can change one’s destiny

B. wehre there’s a will, there’s a way

C. a good scholar can become an official

D. a good beginning is half done

12.(20分）超导现象是20世纪人类重大发现之一，日前我国己研制出世界传输电流最大的高温超导电缆并成功示范运行。

(3）若仍使用上述测量仪器，实验持续时间依旧为t．为使实验获得的该圆环在超导状态的电阻率上限ρ的准确程度更高，请提出你的建议，并简要说明实现方法．

关于问题，公认的三个成分是（）。

A.目标

B.给定

C.障碍

D.方法

王磊申请烟草专卖零售许可证时提交的下列材料中，烟草专卖行政主管部门不应接收的是（）。

A、身份证明

B、资信证明

C、经营场所产权证明

D、住所地房屋产权证明