单项选择题
（） is a machine by which electrical energy is transformed into mechanical energy.
A.An alternator
B.An electric motor
C.A diesel engine
D.A main switchboard
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相关考题
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单项选择题
（） shall be continuously powered and shall have an automatic changeover to a stand by power supply in case of loss of normal power supply.
A.Cooling system
B.Alarm system
C.The air conditioning installation
D.The mooring equipment -
单项选择题
The liquid flowing in the capillary is such that the difference in （） readings taken before the capillary and after it is related to the oil viscosity.
A.pressure
B.velocity
C.flow rate
D.temperature -
单项选择题
The switchboards for a-csystems differ from the d-cswitch gear in that the open type panels are generally（） and the dead-front switch gear is the common rule.
A.permissibly
B.permissible
C.no permissible
D.not permissible
