题目

Not only can ______shut-eye leave us feeling tired and lazy but it can also be damaging our health and looks. A . lacked B . lacking C . lacking of D . lack in 答案：B下列关于电荷的说法中正确的是（　　）A．点电荷就是元电荷B．元电荷是指带电量为1C的电荷C．摩擦起电是通过摩擦创造出等量异种电荷的过程D．不论是摩擦起电还是感应起电，电荷都是守恒的