单项选择题
A.By cooling the oil below the ignition temperature B.By removing the fuel source from the fire C.By excluding the oxygen from the fire D.By increasing the weight of the oil
How do you operate a portable CO2 fire extinguisher?（）....
单项选择题How do you operate a portable CO2 fire extinguisher?（）.
A.Point the horn down B.Turn cylinder upside-down C.Break the rupture disc D.Pull pin，squeeze grip
High-velocity fog（）.A.is a finer，more diffuse water spr...
单项选择题High-velocity fog（）.
A.is a finer，more diffuse water spray than low-velocity fog B.requires that the water pressure be no greater than 60 psi C.produces an effective fog pattern no more than 6 feet beyond the nozzle D.extinguishes a fire by absorbing heat and reducing the supply of oxygen
Halon from extinguishers used on a class B fire，should ...
单项选择题Halon from extinguishers used on a class B fire，should be directed（）.
A.at the top of the flames B.at the base of the fire near the edge C.in short quick bursts D.toward the upwind side of the fire
