单项选择题
An oil water monitor is required in order to measure （）.
A.the oil content in water B.the water content in fuel oil C.the water level in bilge well D.the oil level in bilge well
单项选择题 The boiler is fired （） the demand for steam exceeds that available from exhaust gas heating.
单项选择题 Gear pumps are （） because they discharge a near constant amount of liquid regardless of pressure.
单项选择题 Keep compartment （） as the gas given off can be dangerous.
