当变压器的冷却器全部失去电源时，潜油泵及风扇全部停止运行，变_爱下问搜题

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问题单项选择题

当变压器的冷却器全部失去电源时，潜油泵及风扇全部停止运行，变压器在额定负载条件下，允许运行时间为（）

A、10min

B、20min

C、30min

D、40min

答案

参考答案：B

选择题

It was an exciting moment for these football fans this year, ______ for the first time in years

their team won the World Cup.

A．that

B．while

C．which

D．when

问答题简答题

捣固作业应该注意哪些事项？