对于中型企业,供配电距离较长,用电设备容量较大,有时可能有高压用电设备,一般采用()供电。
A、380V
B、220V
C、l0kV
D、36kV
参考答案:C
按照生产性噪声种类,发电机发出的噪声属于( )噪声。
A.空气动力 B.机械性C.电磁性 D.涡流
He didn’t to return earlier than 3 o’clock.()
A. was not expected
B. did not expect
C. was expected not
D. was not expecting