open-type
hermetic
A and B
None of the above
第1题：
If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably _____.
A.misalignment or worn main bearings
B.insufficient cylinder lubrication
C.defective or poorly fitted valves
D.All of the above
第2题：
What could be a result of insufficient lubrication of lifeboat winches and davits ________．
A.Moisture accumulation in winch motor damaging the electrical wiring
B.Freezing of gears in cold weather
C.Corroding of sheaves on the davits so they will not rotate
D.All of the above
第3题：
Our starboard derrick boom of hatch No.4 is badly cracked ____ that it has become entirely useless.
A.at its goose neck to such a extent
B.at it’s goose to such an extent
C.at it’s goose neck for such a extent
D.at its goose neck to such an extent
第4题：
leaking discharge valve
jammed suction valve
tripped overload relay
broken discharge un-loader
第5题：
外流活门的哪个马达直接受座舱增压面板控制？
第6题：
The primary function of an electric motor is to ______.
A.develop torque
B.generate high voltages
C.produce a magnetic field
D.generate high electrical resistance
第7题：
下面关于motor函数运用错误的一项是（）。
第8题：
The electrical components for each single crane are installed in its ______.
A.crane house
B.machinery base
C.turntable
D.All of the above
第9题：
Moisture accumulation in winch motor damaging the electrical wiring
Freezing of gears in cold weather
Corroding of sheaves on the davits so they will not rotate
All of the above
第10题：
to give off；which
giving off；which
to give off；that
giving off；that