单项选择题
After extinguishing a paint locker fire using the fixed CO2 system，the next action is to have the space（）.
A.opened and burned material removed B.left closed with vents off until all boundaries are cool C.checked for oxygen content D.doused with water to prevent reflash
单项选择题 After extinguishing a fire with CO2，it is advisable to（）.
单项选择题 According to the regulations，what fire safety control feature is required in quick-closing shut off valves?（）
单项选择题 A vessel is constructed with a steel hull and an aluminum superstructure. Which statement is TRUE?（）
