单项选择题
A.off-center B.on the centerline C.completely flooded D.open to the sea above and below the waterline
A.air bottle for breathing B.whistle and hand held flare C.whistle,strobe light and reflective tape D.whistle,hand held flare and sea dye marker
A.air bottle for breathing B.orange smoke canister C.whistle,light and retroreflective material D.sea dye marker