单项选择题
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
Which characteristic is an advantage of Halon as a fire...
单项选择题Which characteristic is an advantage of Halon as a fire extinguishing medium?（）
A.Electrically non-conductive B.Relatively inexpensive C.Effective against chemicals containing an oxidizer D.All of the above
Which action is routinely performed at the annual servi...
单项选择题Which action is routinely performed at the annual servicing and inspection of a dry-chemical cartridge-operated portable fire extinguisher?（）
A.Insure the chemical is powdery B.Replace the cartridge C.Pressure test the discharge hose D.Test the pressure gauge for proper operation
