单项选择题
A.ammeter B.voltmeter C.synchroscope D.A+B+C
When the bearing becomes dry from lack of oil, the moto...
单项选择题When the bearing becomes dry from lack of oil, the motor shaft may heat to （）an extent （） it welds itself to the bearing.
A.either；or B.neither；nor C.such；that D.so；that
An indicator on the main switchboard should show （） the...
单项选择题An indicator on the main switchboard should show （） the emergency battery is in service or not.
A.that B.when C.if D.whether
When a sudden increase in steam demand comes to normal,...
单项选择题When a sudden increase in steam demand comes to normal, the drum pressure will and water level in the drum will（）.
A.rise, rise also B.rise, drop C.drop, rise D.drop, drop also
