What would NOT be a distress signal?()
A.MAYDAY sent by radiotelephone
B.Continuous sounding of fog horn
C.Green star shells fired from a launcher
D.Square flag and ball in a vertical line
参考答案:C
What would NOT be a distress signal?()
A.MAYDAY sent by radiotelephone
B.Continuous sounding of fog horn
C.Green star shells fired from a launcher
D.Square flag and ball in a vertical line
参考答案:C