电机的励磁绕组发生短路时,电动机的转速(),使电动机过热。
A、不变
B、增大
C、降低
参考答案:B
The Mid-autumn Day happening to _________along National Day, it is estimated that it will be 38 years ________ we can experience such a coincidence again.
A.make up, when
B.Come across, that
C.pick up, since
D.come along, before
室内消防竖管直径不应小于DN()。
A.60
B.80
C.100
D.110