单项选择题
On a ship，firefighting equipment must be inspected once every（）.
A.three months B.six months C.twelve months D.eighteen months
单项选择题 On a ship，a fixed carbon dioxide or other approved system must be installed（）.
单项选择题 On a ship，a fire drill shall be conducted once every（）.
单项选择题 On a ship，a cabinet or space containing the controls or valves for the fixed firefighting system must be（）.
