单项选择题
A.Poor combustion
B.High cylinder oil consumption
C.Leaking exhaust valves
D.All of the above
单项选择题 Which of the following problems should be taken when cleaning the air filter on a diesel engine equipped with a turbocharger?（）
单项选择题 Which of the following problems may occur if the clearance between a piston and cylinder liner is insufficient?（）
单项选择题 When installing rings on a diesel engine piston, you should check the ring（）