单项选择题
A.carbonization of oils from the combustion chambers
B.emulsions of lube oil and water
C.coagulation of unburned fuel below the piston rings
D.all of the above
单项选择题 A diesel engine is turned at normal cranking speed, but fails to fireThis can occur from （）
单项选择题 Which of the following statements represents the reason for rolling over a diesel engine with the cylinder indicator cocks open prior?（）
单项选择题 In a diesel engine, a positive displacement type blower is usually （）