电厂厂用电源切换期间，厂用工作电源和备用电源之间有短时并联运行的切换是（）。
参考答案：并联切换
— Could you tell me ______?
— Yes. It’s next to the supermarket.
A．where the post office is
B．where was the post office
C．where is the post office
D．where the post office was
关键工序即为含有（）的工序。
A、焊接过程
B、特殊过程
C、关键过程
D、难加工过程
