题干
The number of people ________ this happens is not very large.
A：with whom
B：to which
C：to whom
D：on which
答案(点此获取答案解析）
C
轴上场强E随位置
其中k为大于0的常数，单位为V/m2，
处由静止释放．若不考虑其它力的作用．则试探电荷 ( )