单项选择题
Fires in escaping flammable gas are quickly brought under control by（）
A.stopping the flow of gas B.reducing the chemical chain reaction C.increasing the oxygen supply D.cooling below the autoignition point
单项选择题 If a fire occurs in the boiler room because of a leaking fuel line to a burner, you shut off the fuel using the（）
单项选择题 Spontaneous combustion could occur in（）
单项选择题 All classes of fires can be safely combated using（）
