单项选择题
A.Safety alarm B.Distress alarm C.Fire drill alarm D.General emergency alarm
PAN-PAN repeated three times over the radiotelephone in...
单项选择题PAN-PAN repeated three times over the radiotelephone indicates which type of message will follow?（）.
A.Distress B.Safety C.All clear D.Urgency
Is extra power available（）emergency while maneuvering?A...
单项选择题Is extra power available（）emergency while maneuvering?
A.for B.in C.during D.to
A man aboard a vessel，signaling by raising and lowering...
单项选择题A man aboard a vessel，signaling by raising and lowering his outstretched arms to each side，is indicating（）.
A.danger，stay away B.all is clear，it is safe to pass C.the vessel is anchored D.a distress signal
