单项选择题
A person who sees someone fall overboard should（）.
A.immediately jump in the water to assist the individual B.go to the bridge for the distress flares C.run to the radio room to send an emergency message D.call for help and keep the individual in sight
单项选择题 A man aboard a vessel，signaling by raising and lowering his outstretched arms to each side，is indicating（）.
单项选择题 A distress signal（）.
