增加发电机的励磁电流,便可以增大发电机的()输出。
A.无功
B.有功
C.电流
D.转速
参考答案:A
-----I forget the name of an old school friend at the party.
-----_____. It must have been very embarrassing.
A.Take it easy
B.That’s too bad
C.Nothing serious
D.Don’t mention it
冶金铁路运输在高炉下作业时速()公里。
A、15
B、10
C、5
D、3