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單項(xiàng)選擇題

Diesel engine ‘blow-by’ into the crankcase is caused by excessive ring（）

A.back clearance
B.side clearance
C.gap clearance
D.taper clearance

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單項(xiàng)選擇題

Heavy residual fuel oils are heated prior to centrifuging to （）

A.reduce fuel weight
B.increase specific gravity
C.separate fuel from lube oil
D.reduce fuel viscosity

單項(xiàng)選擇題

In a diesel engine, blow-by is generally the result of worn（）

A.valve guides
B.oil control rings
C.valve seats
D.compression rings