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單項選擇題

If the chemical analysis of a lube oil sample taken from a diesel engine indicates an increased neutralization number, the （）.

A.acidity has increased
B.viscosity has decreased
C.demulsibility has improved
D.foaming is guaranteed to occur

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單項選擇題

When an auxiliary boiler is panting and emitting black smoke, you should （）.

A.increase the fuel oil temperature
B.decrease the fuel oil temperature
C.decrease the fuel oil supply pressure
D.increase the air supply

單項選擇題

With regards to a diesel engine crankcase explosion, the most violent is the（）
(1) primary explosion
(2) secondary explosion

A.(1) only
B.(2) only
C.both (1) and (2)
D.neither (1) or (2)

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