单项选择题
A.use all CO2 available to cool the surrounding area
B.stand by with water or other agents
C.thoroughly ventilate the space of CO2
D.jettison all burning materials
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?（）
单项选择题 A squeeze-grip type carbon dioxide portable fire extinguisher has been partially discharged. It should be（）.