问题 选择题

M、N为正点电荷Q的电场中某直线上的两点,距Q的距离如图所示,一试验电荷q在Q的作用下沿该直线由M向Q做加速运动.下列相关说法中正确的是(  )

 

A.试验电荷q带正电

B.试验电荷q在N点的加速度是在M点加速度的4倍

C.N点电场强度是M点电场强度的2倍

D.试验电荷q在N点的电势能比在M点的电势能大

答案

答案:B

实验电荷从M运动到N,做加速运动,故带负电,电场力做正功,电势能减小,由易知B正确]

完形填空

When many people from other countries come to America for the first time, they meet many difficulties. They can't speak much English, and they don't know much  56  America. Sometimes, they make mistakes.

Sally   57  to America from Korea years ago. Because her English wasn' t good, she was afraid to ask the ways. So she usually  58  find the places in America. Then she hoped she could see something that she knew,   59  she couldn' t. Then she began to cry and miss her own country because she  60 had this kind of problems in Korea. She could find the places easily in  61 .

Little Henry came to America from Thailand with his parents. He didn' t know   62 to put the money into an American bank at first. When he grew  63 and knew more English, he finally put the money into an American bank successfully (成功地).

There   64  many other things about America, and the people from other   65  can' t understand those things when they come to America for the first time. They need to learn more.

小题1:A. at                     B. about                    C. for

小题2:A. wrote                  B. talked                   C. came

小题3:A. can                   B. could                   C. couldn't

小题4:A. but                    B. or                       C. so

小题5:A. usually                B. never                   C. always

小题6:A. America               B. Korea                    C. Thailand

小题7:A. how                 B. what                      C. where

小题8:A. thinner               B. older                     C. heavier

小题9:A. is                   B. was                      C. are

小题10:A. countries             B. families                    C. banks

选择题