以淡水作为冷却介质的活塞冷却机构应采用下列机构（）。A.铰链式B.套管式C.固定喷管式D.连杆钻孔喷

result being that an annular space formed between the piston rod and the pipe.

A.less than

B.greater than

C.equal to

D.twice larger than

t cooler locations, flow control and preheating, but with a central cooler and one additional set of pumps.

A.the central cooling system, different

B.the central cooling system, the same

C.the open cooling system, different

D.the open cooling system, the same

Shore power must be_____ during dock repair.

A.disconnected

B.switched off

C.cut off

D.connected

he heat energy to mechanical energy.

A.the burning of the fuel; medium shaft

B.fuel spray; fresh air

C.fuel; fuel spray

D.the burning of the fuel; the burned gas mixture

滤油器的公称压力是指其________所能承受的最大工作压力。

A.壳体

B.密封元件

C.滤芯

D.A和B

If two A.Cgenerators are to be operated in parallel, the load is distributed evenly by .

A.means of rheostat the governor settings

B.a balance coil excitation

C.adjusting the governor settings

D.changing excitation

Defective governor in a diesel engine may lead to .

A.smoky exhaust

B.starting failure

C.ignition relay

D.over speed

mstances, there are also openings known as , in the part of the cylinder liner.

A.scavenging air ports; exhaust ports

B.inlet ports; scavenging air ports

C.scavenging air ports; inlet ports

D.exhaust ports; inlet ports

ternal combustion engines is the ________.

A.method of supplying air

B.cooling system

C.method of igniting fuel

D.valve operating mechanism

旋涡泵初次使用时向泵内灌水主要是为了________。

A.能够自吸

B.冷却好

C.润滑

D.提高容积效率