单项选择题
Foam extinguishes a fire by（）.
A.smothering the burning material B.chemical combination with burning material C.absorbing the burning material D.organic destruction of the burning material
单项选择题 Foam extinguishes a fire by（）.
单项选择题 Flames from small leaks of LFG may be extinguished by（）.
单项选择题 Flame screens are used to（）.
