单项选择题
A.sweep flames away with water spray B.shut off the leak C.use a chemical foam fire extinguisher D.call the local fire department
A.should be worn while fighting a fire B.can be used in atmospheres deficient in oxygen C.filter contaminants from air that is to be breathed D.may be substituted for a self-contained breathing apparatus
A.8the heat of a fire melting the link B.a break-glass and pull-cable system C.electrical controls on the bridge D.a mechanical arm outside the vent duct