单项选择题
Fire hose couplings（）.
A.are made of bronze，brass，or soft alloy metals B.should be painted red in order to identify hose lengths C.are specially hardened to prevent crushing D.should be greased frequently
单项选择题 Fire fighting equipment requirements for a particular vessel may be found on the（）.
单项选择题 Fire extinguishing agents used on Class C fires must be（）.
单项选择题 Fire extinguishers on inspected vessels are numbered by size I through V，with I being（）.
