题目

电场中有一点P，下列说法中正确的是    （A）若放在P点的电荷的电量减半，则P点处的电场强度减半    （B）若P点没有检验电荷，则P点的电场强度为零    （C）P点的电场强度越大，则同一电荷在P点受到的电场力越大    （D）P点的电场强度方向与该点放置检验电荷的带电性质有关  答案：C解析:略  —Hi, Bruce. Here is a letter for you.   —Thanks. I wonder          . A. who the letter was from          B. who was from the letter C. who was the letter from          D. who from the letter was