单项选择题
On a ship，a cabinet or space containing the controls or valves for the fixed firefighting system must be（）.
A.posted with instructions on the operation of the system B.ventilated and equipped with explosion-proof switches C.painted with red and black diagonal stripes D.equipped with a battery powered source of emergency lighting
单项选择题 On a class B fire，which portable fire extinguisher would be the LEAST desirable?（）
单项选择题 Oily rags stored in a pile that is open to the atmosphere are a hazard because they may（）.
单项选择题 Normally，potable water systems are connected directly to the（）.
