单项选择题
At which of the following locations would a duplex pressure gage most likely be located?（）
A.Fuel oil service pump discharge B.Fuel oil strainer C.Fuel oil heater D.Fuel oil flow meter
单项选择题 The function of lubricating oil is to （）
单项选择题 Main propulsion engine lube oil sumps should be constructed （）
单项选择题 The ash content of a fuel oil is significant to the operating engineer because it （）
