The camshaft on a four-stroke/cycle diesel engine provides a means to operate the （）.

A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) scavenging air is cooling the exhaust gases (2) exhaust cycle time is longer

A.(1) only
B.(2) only
C.both (1) and (2)
D.neither (1) nor (2)

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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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