单项选择题
Which of the listed substances can be satisfactorily removed from diesel fuel by centrifuging?（）
A.Sludge B.Gasoline C.Fuel oil D.Lube oil
单项选择题 The amount of fuel delivered by a unit injector is controlled by the （）
单项选择题 Cast iron pistons used in large propulsion diesel engines are constructed with （）
单项选择题 The major cause of trouble in a mechanical-hydraulic governor is contamination of the hydraulic fluid by （）
