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问题 选择题

真空中，两个相距L的固定电荷E、F所带电荷量分别为QE和QF，在它们共同形成的电场中，有一条电场线如图实线所示，实线上的箭头表示电场线的方向．电场线上标出了M、N两点，其中N点的切线与EF连线平行，且∠NEF＞∠NFE，则（　　）

A．E带正电，F带负电，且QE＜QF

B．在M点由静止释放一带正电的检验电荷，检验电荷将沿电场线运动到N点

C．过N点的等势面与过N点的切线垂直

D．负检验电荷在M点的电势能大于在N点的电势能

答案

A、N点的场强是由E、F两电荷在产生场强的叠加，根据N点的切线与EF连线平行，知E带正电，F带负电，则电荷E在N点电场方向沿EN向上，电荷F在N点产生的场强沿NF向下，合场强水平向右，可知F电荷在N点产生的场强大于E电荷在N点产生的场强，而NF＞NE，所以QF＞QE．故A正确．

B、只有电场线是一条直线，且初速度为0或初速度的方向与电场平行，其运动轨迹才与电场线重合．而该电场线是一条曲线，所以运动轨迹与电场线不重合．故在M点由静止释放一带正电的检验电荷，不可能沿电场线运动到N点．故B错误．

C、因为电场线和等势面垂直，所以过N点的等势面与过N点的切线垂直．故C正确．

D、沿电场线方向电势逐渐降低，UM＞UN，再根据Ep=qU，q为负电荷，知EpM＜EpN．故D错误．

故选C．

阅读理解

Betty is not a traditional American beauty. She is unfashionable, has thick red glasses, untidy hair and large metal braces (牙套) on her teeth. But this hasn’t stopped her from becoming one of America’s favorite TV characters. So how did she manage to do it?

The answer is that charm can be more attractive than beauty. Betty is the main character in a TV show Ugly Betty. The show is about her life as an office worker at a fashion magazine in New York.

The TV show has just started. Betty has many exciting experiences and romantic stories. Betty is often looked down on and laughed at by the people around. But she manages to do better than others with her hard work, charm and wisdom. The show tells us about how a girl goes from an ugly young duck into a beautiful swan.

Though you may know the ending of the show from the beginning and the story is familiar to many of us, it has still been a big success in the USA. It has attracted a large number of viewers and won two Golden Globes awards, one of the highest honors for a television program in the USA. “I think you can see a bit of Betty in all of us, and I mean men as well, because it’s about the underdog (弱者) ”, says Ashley Jensen, who plays one of the characters on the show.

The program is so popular because of the performance of the 23-year-old actress America Ferrera who plays the role of Betty. She brings the character alive on the screen.

小题1:Betty is popular because of                   .

A．her clothes

B．her charm

C．her personality

D．her appearance小题2:In Paragraph 4, the underlined word “it” refers to (指的是)                   .

A．the beginning

B．the ending

C．the story

D．the show小题3:Which is the reason for the success of the show?

A．A large number of viewers.

B．Her life as an office worker.

C．The wonderful performance.

D．Two Golden Globes awards.小题4:Which of the following is NOT true according to the passage?

A．Betty is a girl of wisdom.

B．Betty acts as a beautiful swan on the show.

C．Betty is an American favourite TV character.

D．Betty is often looked down on by the people around.小题5:What can be the best title for the passage?

A．Beauty from within.

B．A romantic story.

C．An ugly girl.

D．An exciting experience.
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单项选择题 A1/A2型题

诊断慢性肾盂肾炎时，下列哪项是不正确的 （）

A.静脉肾盂造影中可见到肾盂肾盏变形缩窄

B.必有尿路刺激症状（尿急、尿频、尿痛）

C.无全身症状，只有尿培养反复多次阳性

D.肾小管功能可持续损害

E.可有高血压、水肿、肾功能减退
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