以下说法正确的是？（ ）
A．在电场中，电场强度大的点，电势必高。
B．一带电粒子只受电场力作用，在电场中运动时，电势能一定变化。
C．电场中电场强度大的地方，沿电场线方向电势降落快。
D．电荷置于电势越高的点，所具有的电势能也越大。
答案：C
题目分析：电势的高低与电场强度无关，它可以由人为的规定，A错误，当带电粒子在等势面上移动时，过程中受到电场力作用，但是电场力不做功，电势能不变化，B错误，根据公式
可得电场中电场强度大的地方，沿电场线方向电势降落快。C正确，根据公式
可得负电荷在电势高的地方电势能很小，D错误，
点评：电势的高低是人为规定的，电场和电势之间没有关系
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| I was sitting in the surgical waiting area at the hospital waiting for word of my wife's operation. The small room was filled with other families and friends who were__1__waiting to hear how their loved ones were doing. There was a young boy sitting quietly in the__2__.He held a small box of__3__in one hand and a tablet( 写字板)in the other. Every so often he'd place the tablet on his lap and draw something. As the hours passed I began to see the room almost__4__.And there was a strange silence. "Daddy,when is Mommy going home?"the young boy asked,breaking the__5__. "Tomorrow,"his father replied. The boy picked up his crayons and__6__something on the tablet. I __7_him as he moved his feet back and forth,looking up at the ceiling and then toward the sunshine－filled window."When's__8__,Daddy?"he asked. His father__9__him over to sit by him. "Come,___10__here next to me,"he said with a gentle tone in his voice. __11__his things,the little boy walked slowly to his father's side from the corner. The man_12__out and held his son by his shoulders. "There are three days in life. Yesterday,today and tomorrow. One is over and done,one we live in,the other we__13__.We can't live in yesterday,but if we are happy enough today, we will be even happier tomorrow,"he said in an attempt to__14__the boy. The little boy looked at him for a moment and said,"If Mommy is going home tomorrow, I'll be__15__. So,I want it to be tomorrow already, Daddy." Now hanging on every word of this__16__,I leaned forward to hear his response. It was __17__. "Son,the one great thing about today is once it__18__,it is already almost tomorrow." I thought about how__19__it was. Even in my adult life. I still live waiting for what tomorrow may__20__.Now I know that it is already "almost tomorrow." | |||
| ( )1.A.eagerly ( )2.A.chair ( )3.A.gifts ( )4.A.dark ( )5.A.promise ( )6.A.wrote ( )7.A.followed ( )8.A.today ( )9.A.knocked ( )10A.stand ( )11.A.Gathering ( )12.A.got ( )13.A.spend ( )14.A.frighten ( )15.A.happier ( )16.A.story ( )17.A.humorous ( )18.A.ends ( )19.A.meaningful ( )20.A.happen | B．patiently B．corner B．toys B．full B．rule B．drew B．found B．yesterday B．ordered B．sit B．Forgetting B．took B．waste B．satisfy B．calmer B．argument B．silly B．starts B．important B．come | C．happily C．distance C．chalks C．empty C．record C．printed C．watched C．future C．called C．lie C．Saving C．set C．kill C．persuade C．smarter C．conversation C．positive C．passes C．interesting C．bring | D．curiously D．shadow D．crayons D．clean D．silence D．carved D．caught D．tomorrow D．pulled D．sleep D．Choosing D．reached D．expect D．warn D．sadder D．discussion D．perfect D．lasts D．fantastic D．need |