单项选择题
A.flashlight B.combustible gas indicator C.self-contained breathing apparatus D.fire axe
A.Paints，varnish，or other liquid flammables are stowed in a dry stores locker B.Inert cargoes such as pig iron are loaded in a wet condition C.Oily rags are stowed in a metal pail D.Clean mattresses are stored in contact with an electric light bulb
A.has left hand twist B.has inside threads on both ends C.has outside threads on both ends D.takes two men to operate