单项选择题
A.gate valve B.pressure gauge C.check valve D.strainer
The discharge from a carbon dioxide fire extinguisher s...
单项选择题The discharge from a carbon dioxide fire extinguisher should be directed（）.
A.at the base of the flames B.at the center of the flames C.to the lee side of the flames D.over the tops of the flames
The disadvantage of using CO2 is that the（）.A.CO2 does ...
单项选择题The disadvantage of using CO2 is that the（）.
A.CO2 does not cool the fire B.cylinders are regulated pressure vessels C.C02 is not effective on class B fires D.C02 is not effective on class C fires
The collision bulkhead shall be of（）.A.water-tightB.air...
单项选择题The collision bulkhead shall be of（）.
A.water-tight B.air-tight C.fire-tight D.oil-tight
