单项选择题
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
The boiler is fired （） the demand for steam exceeds tha...
单项选择题The boiler is fired （） the demand for steam exceeds that available from exhaust gas heating.
A.whenever B.however C.wherever D.whether
Gear pumps are （） because they discharge a near constan...
单项选择题Gear pumps are （） because they discharge a near constant amount of liquid regardless of pressure.
A.negative displacement type B.turbine type C.positive displacement type D.mixed-flow type
Keep compartment （） as the gas given off can be dangero...
单项选择题Keep compartment （） as the gas given off can be dangerous.
A.well ventilated B.well clean C.in good order D.more room
