单项选择题 An individual injection pump is designed for variable beginning and constant ending of injectionFor diesel engines operating at constant speeds, the start of injection will（）

单项选择题 The purpose of the compensating adjustment used in a diesel engine hydraulic governor is to （）

单项选择题 If a hydraulic governor has been refilled with oil, the engine should be operated until it reaches normal temperaturethen the air should be purged, and the（）