单项选择题
A fixed carbon dioxide extinguishing system for a machinery space，designed WITHOUT a stop valve in the line leading to the protected space，is actuated by（）.
A.one control B.two controls C.three controls D.none of the above
单项选择题 A fishing vessel displaying the lights shown is（）.
单项选择题 A fishing vessel casualty must be reported to the Coast Guard if it involves（）.
单项选择题 A fire pump may be used for other purposes if（）.
