一、填空题1．自然界中只存在电荷；人们把用毛皮摩擦过的橡胶棒上所带的电荷ml做．；同种电荷互相，异种电行互相2．三个带电的通草球，其中A排斥B，C吸引B，说明A和C带＿种电荷，若B带正电荷，则A带＿电荷，C带＿电荷．3．原来不带电的丝绸和玻璃棒摩擦后立即分开，玻璃棒上 First, fill in the blank 1. There is only charge in nature; people do the charge ml on a rubber rod that has been rubbed with fur. ; The same kind of charge each other, different kinds of electricity and each other 2. Three charged grass ball, where A rejects B, C attracts B, indicating that A and C have _ kind of charge. If B has positive charge, then A has _ charge and C has _ charge. 3. The original uncharged silk and glass rods were separated immediately after friction, on glass rods