单项选择题
A.A red parachute flare B.A red hand-held flare C.A flashlight D.A lantern
A.Hand-portable fire extinguisher B.Life preserver C.Immersion suit D.Lifeboat oar
A.Only a light layer of clothing may be worn underneath B.They provide sufficient flotation to do away with the necessity of wearing a life jacket C.They should be tight fitting D.A puncture in the suit will not appreciably reduce its value