单项选择题
Except in rare cases，it is impossible to extinguish a shipboard fire by（）.
A.removing the heat B.removing the oxygen C.removing the fuel D.interrupting the chain reaction
单项选择题 Control valves of a CO2 system may be located within the protected space when（）.
单项选择题 CO2 cylinders，which protect the small space in which they are stored must（）.
单项选择题 CO2 cylinders equipped with pressure actuated discharge heads will discharge automatically when（）.
