单项选择题
A.a dirty lube oil strainer
B.internal water leaks
C.an oil suction line restriction
D.excessive wears of the cooling water pump
单项选择题 The reversing cams of some four-stroke/cycle diesel engines are brought into position by （）
单项选择题 A diesel engine is equipped with an isochronous hydraulic governorA decrease in load will cause the engine speed to （）
单项选择题 The arrangement and shape of the cams on a diesel engine camshaft directly control which of the listed groups of operating conditions?（）