单项选择题
A.CO2 B.Foam C.Dry Chemical D.Water
Which extinguishing agent is effective in combating an ...
单项选择题Which extinguishing agent is effective in combating an isoprene fire?（）
A.Dry chemicals B.CO2 C.Foam D.All the above
Which extinguishing agent is best for use on a magnesiu...
单项选择题Which extinguishing agent is best for use on a magnesium fire?（）
A.Water B.Sand C.CO2 D.Dry chemical
Which characteristic of Halon is a disadvantage when it...
单项选择题Which characteristic of Halon is a disadvantage when it is used as a fire extinguishing medium?（）
A.Leaves a residue B.Cost，relative to other agents C.Breaks down while under prolonged storage D.Conducts electricity
