动机绕组对机壳和绕组间的绝缘电阻应大于多少兆欧？
参考答案：
0.5兆欧
—_____chapter in Oxford English often consists of four parts．
—That’s right．And this chapter mainly talks about _____environmental problems．
A．The；an
B．An；the
C．the；the
D．A；the
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