A.withB.ofC.onD.overThe ship has a diesel engine（）a sup……

单项选择题The pivot pin at the base of a sheath-screw boom davit must be（）.

A.inserted each time before the booms are cranked out
B.periodically removed for inspection and lubricated
C.replaced at each inspection for certification
D.in the locked position after the boat is cradled and griped down

单项选择题The part of a windlass which physically engages the chain during hauling or paying out is the（）.

A.devil's claw
B.bull gear
C.wildcat
D.cat head

单项选择题The most serious effect of air trapped in a diesel engine jacket water cooling system is that it（）.

A.causes colloid suspension in the cooling water
B.reduces the capability of the lubrication system
C.can form pockets which block the flow of coolant through the system
D.leads to the scuffing of cylinder walls

单项选择题The engine in a covered lifeboat is fueled with（）.

A.kerosene
B.unleaded gasoline
C.diesel oil
D.liquefied gas

单项选择题Sudden unloading of a diesel engine can cause（）.

A.decreased fuel efficiency
B.increased exhaust temperature
C.black smoke
D.overspeed trip