A:it
B:one
C:those
D:Them
在静电感应实验中,取一对用绝缘柱支持的不带电导体A和B,使它们彼此接触,把毛皮摩擦过的橡胶棒C移近导体A.在下列不同操作后判断导体A和B的电性(填“带正电”、“带负电”、“不带电”).
①把A和B分开,然后移去C,此时A____,B____;
②先移去C,然后把A和B分开,此时A____,B____;
③用手摸一下A,把A和B分开,然后移去C,此时A____,B____.
--__________ you __________ in this school for more than ten years?
--Yes, I __________ here in 2002.
23 -5 +87 -3.4 14.5 0 -0.1 +1.3
−314 +11 0.8 -4 −16 0.71 -2.4 922
____