当用电负荷允许中断供电时间要求在( )以内时,应用不间断电源UPS。
A. 0.1s
B. 1s
C. 1.5s
D. 2s
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It is much easier to talk about social change than to ______.
A. bring it down
B. bring it out
C. bring it up
D. bring it about
69()
A. come from
B. result in
C. succeed in
D. depend on
70()
A. suitable
B. value
C. fit
D. worth
发电机组至低压配电柜馈电线路的相间、相对地间绝缘电阻值应大于0.5MQ;塑料绝缘电缆馈电线路直流耐压试验为( ),时间15min,泄漏电流稳定,无击穿现象。
A. 1.4kV
B. 1.2kV
C. 2.8kV
D. 2.4kV