单项选择题
A.cannot be made with salt water B.is heavier than oil and sinks below its surface C.is corrosive and a hazard to fire fighters D.conducts electricity
A.it can break down under high heat and emit noxious fumes B.it will decompose under prolonged storage and lose its effectiveness C.fire has been known to flash back over the surface of an oil fire D.it is ineffective in fighting fires in high-voltage electrical equipment
A.can fit any size hose B.converts a stream of water into a fog C.increases the amount of water reaching the fire D.can spray two streams of water at the same time