单项选择题
The effective pump stroke of an individual port-and-helix fuel injection pump is determined by the （）
A.fuel delivery pressure B.pump plunger diameter C.plunger control rack position D.total pump stroke
单项选择题 The upper section of a piston is called the （）
单项选择题 Pitted reduction gear teeth having a deep blue color with evidence of overheating have been operated with （）
单项选择题 Which of the listed substances can be satisfactorily removed from diesel fuel by centrifuging?（）
