单项选择题
Which of the factors listed has the greatest effect on the mechanical efficiency of a diesel engine?（）
A.temperature of the intake air B.friction within the engine C.mechanical condition of the supercharger D.mechanical condition of the turbocharger
单项选择题 A practical way of checking for excessive fuel injection in one cylinder of an operating diesel engine is to （）
单项选择题 If the compression ratio is increased on any diesel engine, （）
单项选择题 If a used lube oil analysis indicates excessive fuel dilution, the lube oil should be （）
