In large marine diesel engines cylinder oils usually contain additives formulated to impart the （） to clean the rings and grooves.

[单选题]Large marine diesel engines of crosshead construction generally have two systems of lubrication: a total loss system feeding the （） and a recirculation system lubricating the running gear and cooling the piston.A . cylinder liners and piston ringsB .

[单选题]Cylinders of marine diesel engines are normally cooled by （）.A . sea waterB . fine mineral oilC . sanitary waterD . fresh water

[单选题]Marine four-stroke diesel engines are mainly （）.A . of crosshead typeB . of trunk piston typeC . of low speed typeD . all the above

[单选题]_____ the engines, the diesel engine is ____ used engine on boardA．Between / more commonlyB．Among / the most commonlyC．Between / not more commonlyD．Among / not the most commonly

[单选题]D．iesel engines are started by supplying into the cylinders in the appropriate sequence for the required direction.A．cooling waterB．compressing airC．compressed airD．cylinder oil

[单选题]All diesel engines are classified as（）.A . four cycleB . compression ignitionC . vacuum ignitionD . external combustio

[单选题]In diesel engines designed with a crosshead, the motion of the piston rod can be described as （）.A . reciprocating at the piston pin, rotary at the crank pinB . reciprocating at the crank pin, rotary at the piston pinC . straight reciprocationD . str

[单选题]The crankcase of many diesel engines are kept under a slight vacuum by the （）.A . scavenging action of the pistonB . piston type vacuum pump taking suction off a differential manometerC . gland exhausting manometerD . crankcase exhaust fa

[单选题]Lubricating systems for diesel engines are usually designed to initially provide lube oil to the engine （）A . camshaft beatingsB . main bearingsC . piston crownsD . cylinder wall

[单选题]Diesel engines are started by supplying （） into the cylinders in the appropriate sequence for the required direction.A . cooling waterB . compressing airC . compressed airD . cylinder oil