单项选择题
A vessel in distress should send by radio telephone the two tone alarm signal followed immediately by the（）.
A.Distress position B.Spoken words“Mayday，Mayday，Mayday” C.Ship's name D.Ship's call letters
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（）.
单项选择题 A man aboard a vessel，signaling by raising and lowering his outstretched arms to each side，is indicating（）.
