Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.

A．The direction of pressure on the journal in four-stroke engine is continuously

B．positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine

C．four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines

D．Low-stroke engines usually consume less lube oil than four-stroke engines

[单选题]The main bearings are provided with thin-walled （）, lined with a copper-lead alloy.A . steel guidesB . steel shellsC . steel bearing capsD . pig iro

[单选题]Lubrication for the main reduction gears used with diesel engines is usually supplied byA．oil from the main engine sumpB．an independent lube oil systemC．the stern bearing head tankD．the stem bearing sump tank

[单选题]The main function of the lubrication system in to enable （） of a film of oil between the moving parts.A . the informationB . the formationC . the scatterD . the frictio

[单选题]Main bearings are required to support the crankshaft at each （）.A . endB . webC . pinD . journal

[单选题]The bearings used to support the crankshaft are generally called （）A . line shaft bearingsB . connecting rod beatingsC . main bearingsD . support bearing

[单选题]Generally the function of lubrication is to form of a film of lubricant between any two surfaces that have relative （）, so that surfaces dont get touch with each other.A . gravityB . motionC . ratioD . density

[单选题]At 0715 you take the following bearings: Race Rock Light 328°pgc; Little Gull Island Light 249°pgc; Mt. Prospect Antenna 036°pgc. Based on your 0715 fix，which statement is TRUE?（）A . You are to the left of your track lineB . Your fathometer reads abo

[名词解释] 英译汉：lubrication

[单选题]The oil quantity for bearing lubrication should be applied in such an amount as to be sufficient to carry away the （） caused by the friction at the bearings.A . acidsB . additivesC . heatD . gear

[单选题]In a bypass type lubrication system for a diesel engine, the dirty oil line to the centrifuge should be taken from the （）.A . lube oil pump suction lineB . lube oil pump discharge lineC . bottom of the lube oil sumpD . outlet from the lube oil header