单项选择题
A.overlap B.crush C.lap or lead D.protrusion
The usual method of effectively applying foam on a fire...
单项选择题The usual method of effectively applying foam on a fire is by （）.
A.spraying directly on the base of the fire B.flowing the foam down a vertical surface C.sweeping the fire before you with the foam D.spraying directly on the surface of the fire
During the inspection, the starting air valves should b...
单项选择题During the inspection, the starting air valves should be closed （）the engine from turning.
A.to increase B.to speed up C.to prevent D.to reduce
The viscosity regulator controls the fuel oil temperatu...
单项选择题The viscosity regulator controls the fuel oil temperature （）provide oil at the correct viscosity for combustion.
A.in order that B.because of C.in order to D.owing to
