(单选题)20: Copper as well as most metals ____________.
A: is a good conductor
B: is a good insulator
C: are good conductors
D: are good insulators
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(单选题)20: Copper as well as most metals ____________.
A: is a good conductor
B: is a good insulator
C: are good conductors
D: are good insulators
(责任编辑:admin) |