问题 选择题

如图所示,三条虚线表示某电场的三个等势面,其中φ1=10V,φ2=20V,φ3=30V。一个带电粒子只受电场力作用,按图中实线轨迹从A点运动到B点,由此可知

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A.粒子带正电

B.粒子的速度变大

C.粒子的加速度变大

D.粒子的电势能变大

答案

答案:B

完形填空

Which of your two hands do you use most? Very few of us can use __1__  of our hands equally well. Most of us are right-handed. Only about five people ___2___ a hundred are left-handed. New-born babies can grasp(抓住)objects with__3____ of their hands, but in about two years they usually prefer to use their ___4___ hands. Scientists don’t know why this __5___.

Monkeys are our  ___6___  relatives(亲戚)in the animal world. Scientists have found that monkeys prefer to use one of their hands more than the ___7___  ---but it can be either hand. There are as many right-handed monkeys as left-handed___8___  . Next time you visit the zoo, ___9___  the monkeys carefully. You’ll see that some of most them will prefer to use their right hands when they swing(荡秋千), and others will use their left hands. But most human beings use their right hands better and this makes life ___10___ for those who prefer to use their left hands. In fact we live in a right-handed world.

(    )1. A. either     B. both         C. two       D. all 

(    )2. A. from      B. among       C. from among  D. out of

(    )3. A. either     B. neither       C. two       D. all

(    )4. A. two       B. both         C. right     D. left

(    )5. will happen   B. happens      C. take place  D. will take place

(    )6. A. farthest    B. furthest      C. best       D. closest

(    )7. A. other      B. right        C. left        D. two

(    )8. A. one        B. ones        C. monkey    D. people

(    )9. A. look       B. see         C. watch      D. read

(    )10.A. interesting   B. comfortable  C. easy    D. difficult

填空题