单项选择题
A.Dirty lube oil filter
B.Too much piston ring wear
C.High lube oil viscosity
D.Low lube oil temperature
单项选择题 Which of the following operational conditions will occur to the diesel engine lube oil at extremely high temperature?（）
单项选择题 The oxidation by-products forming in diesel engine lube oil can cause （）
单项选择题 Surface irregularities, such as erosion and pitting on injection pump plungers, will（）