单项选择题
The （） of the lubricant should be sufficient to hold the film together, but it should allow the lubricant to flow easily.
A.specific gravity B.viscosity C.acid value D.calorific value
单项选择题 The （） of the diesel oil must not exceed 120 degree Fahrenheit.
单项选择题 The （） is not properly set thus causing either advanced or retarded firing.
单项选择题 The （） engine is used for alternators and some times for main propulsion with a gearbox to provide a propeller of between 90 to 120 rpm.
