Turbocharging of marine diesel engine is achieved by two distinct methods, （） termed the constant pressure and the pulse system.

[单选题]Before a marine diesel engine is started the cylinders and pistons must be （）.A . cooled to appropriate temperatureB . warmed up gradually to appropriate temperatureC . opened up and renewedD . ground and polished

[单选题]The marine diesel engine is a type of diesel engine used on ships The （） of its operation is not very difficult to understand.A . principleB . principalC . causeD . case

[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]In large marine diesel engines cylinder oils usually contain additives formulated to impart the （） to clean the rings and grooves.A . inefficiencyB . oilinessC . detergencyD . purity

[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]_____ 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]The heart of the diesel engine is the （） where the fuel is burnt and the power developed.A . crankcaseB . cylinderC . scavenge boxD . pisto

[单选题]The diesel engine is a type of （）.A . turbine engineB . gas turbineC . steam engineD . internal combustion engine

[单选题]Pistons of marine medium speed diesel engines may be made of （） in order to keep the weight down for balancing purpose at high speed.A . leadB . forged steelC . alloy steelD . aluminum alloy

[单选题]F．or a continuous operation diesel engine, a duplex filter unit would be the best arrangement becauseA．changing filter elements would not interrupt engine operationB．filtering occurs twice in each pass of oil through the systemC．clogging will not occ