一、填空题 1.物体具有____的性质,我们就说物体带了电,用摩擦的方法使物体带电叫做_____. 2.用一个带电的小球去靠近另一个塑料泡沫小球,如果出现____现象,不能断定塑料泡沫小球是否带电;如果出现_____现象,可以断定塑料泡沫小球一定带电. 3.在图4-1所示电路中,A是___,B是___,L是___,E是___,S控制___,S_1控制___,S_2控制___. First, fill in the blank title 1 objects ____ nature, we say that objects with electricity, the friction method to make the object called _____. 2. With a charged ball to go near another plastic foam ball, If ____ phenomenon occurs, can not determine whether the plastic foam beads are charged; _____ phenomenon can be concluded that plastic foam beads must be charged 3. In the circuit shown in Figure 4-1, A is ___, B Is ___, L is ___, E is ___, S controls ___, S_1 controls ___, S_2 controls ___.