单项选择题
A.fixed foam systems to be ineffective B.faster cooling of the fire C.the accumulation of explosive gases D.the fire to spread through the ventilation system
Before using a fixed CO2 system to fight an engine room...
单项选择题Before using a fixed CO2 system to fight an engine room fire，you must（）.
A.secure the engine room ventilation B.secure the machinery in the engine room C.evacuate all engine room personnel D.All of the above
Before a tank is to be crude oil washed，the oxygen cont...
单项选择题Before a tank is to be crude oil washed，the oxygen content in the tank must be measured at a position（）.
A.immediately above the level of the oil B.at the top of the tank C.in the vent riser D.one meter from the deck
Backfire flame arrestors are installed on（）.A.fuel tank...
单项选择题Backfire flame arrestors are installed on（）.
A.fuel tanks B.spark plugs C.carburetors D.distributors
