单项选择题
A.the engine crankcase B.the engine scavenge boxes C.drain tanks D.fuel tanks
A viscosity regulator used for an engine is usually pro...
单项选择题A viscosity regulator used for an engine is usually provided in order to （） for an engine burning heavy fuel oil.
A.regulate the fuel supply B.maintain a constant fuel viscosity at the fuel valves C.maintain efficient cooling D.alter the fuel density
A manometer is used to measure （）.A.pressureB.temperatu...
单项选择题A manometer is used to measure （）.
A.pressure B.temperature C.volume D.specific gravity
"gauge pressure" means（）.A."vacuum"B."the excess of pre...
单项选择题"gauge pressure" means（）.
A."vacuum" B."the excess of pressure above atmosphere" C."figure on a gauge" D.Any of the above
