单项选择题
Aboard a survival craft，ether can be used to（）.
A.start the engine in cold weather B.aid in helping personnel breathe C.prime the sprinkler system D.prime the air supply
单项选择题 A vessel in distress should send by radio telephone the two tone alarm signal followed immediately by the（）.
单项选择题 A sweep oar is an oar that is（）.
单项选择题 A person who sees someone fall overboard should（）.
