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單項(xiàng)選擇題

The emulsion of the oil is mainly caused by （）.

A.the solid impurities of large particle
B.the solid impurities of fine particle
C.the water content
D.both water and solid impurities

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單項(xiàng)選擇題

Impurities in the fuel oil will affect the operation of the engine, which has （） the use of separator and some other devices.

A.brought about
B.caused for
C.resulted from
D.led

單項(xiàng)選擇題

The lube oil to lubricate the surfaces of the cylinder liners is spread over by the （）.

A.sliding piston rings
B.engines camshaft
C.small pumps
D.forced feed system