单项选择题
A.Decrease the air density
B.Increase the exhaust temperature
C.Decrease the lube oil temperature
D.Increase the air density
单项选择题 Which harmful consequence may be the result of lube oil sludge accumulation? （）
单项选择题 High cylinder firing pressure, accompanied by low exhaust temperature, can result from （）
单项选择题 One end of a cylinder for a medium or high-speed diesel engine is sealed by the piston and rings, the other end is sealed by the （）