单项选择题
A.a spindle lubricator
B.an oil jet
C.internal splashing
D.drilled passages in the crankshaft
单项选择题 The rate of cylinder lubricating oil metered to each cylinder of a large low-speed main propulsion diesel engine is （）
单项选择题 The crankcases of many diesel engines are kept under a slight vacuum to （）
单项选择题 Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?（）