单项选择题
Flame screens are used to（）.
A.contain flammable fumes B.protect firefighters from flames C.prevent flames from entering tanks D.keep flames and sparks from getting out of an engine's exhaust system
单项选择题 Fixed CO2 systems would not be used on crew’s quarters or（）.
单项选择题 Firefighting foam is only effective when the foam（）.
单项选择题 Fire may be spread by which means?（）.
