单项选择题
CO2 extinguishes a fire by （）.
A.a blanket of bubbles formed on the surface of the fire B.smothering C.cooling D.isolating the heat from the fuel
单项选择题 How long warning must be provided by the CO2 warning Mann before CO2 is discharged into a space （）.
单项选择题 Which statement regarding garbage disposal is correct?（）
单项选择题 The sections of an Oil Record Book proceeding the log pages contain a （）.
