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
单项选择题 Which extinguishing agent is best for use on a magnesium fire?（）
单项选择题 Which characteristic of Halon is a disadvantage when it is used as a fire extinguishing medium?（）
单项选择题 Which characteristic is an advantage of Halon as a fire extinguishing medium?（）
