额定功率（rated power）（）的热水锅炉，给水应除氧

A.power output

B.friction and wear

C.indicated pressure（指示压力）

D.rated horsepower

The power factor of an AC generator operating singularly is determined by the_______ .

A.connected load

B.prime mover speed

C.field excitation

D.generator's rated voltage

A. There is a fire hazard potential if a power outage occurs.

B. The last system plugged into the UPS will not be provided any power.

C. The UPS will draw more power from the circuit to compensate.

D. The runtime of the UPS will be insufficient if a power outage occurs.

Compared to a constant pitch propeller, a controllable pitch propeller

A.more efficiently uses available engine power

B.operates at a lower efficiency at a fixed speed

C.produces the same torque at lower engine power

D.develops its rated power at a lower speed

A. The computer is unable to work in the US because of EU licensing arrangements

B. The power supply needs to be replaced with one rated for 110 watts

C. The power supply needs a power inverter to handle the change in cycles

D. The power supply voltage needs to be switched to 110 from 220

A. emergency lighting for occupied areas,navigation lights

B. the driving motors of the emergency bilge pump,fire pumps,and steering gear

C. communications systems and alarm systems

D. all of the above

A.输出的机械功率 output mechanical power

B.输入的机械功率input mechanical power

C.输入的电功率input electric power

D.输出的电功率output electric power

A.Under-current

B.Over-current

C.Over-voltage

D.Under-voltage