单项选择题
Which is NOT a distress signal? （）
A.A continuous sounding with any fog signal apparatus B.A signal sent by radiotelephone consisting of the spoken word "Mayday" C.An International Code Signal of N.C. D.The firing of green star rockets or shells
单项选择题 Which is a distress signal? （）
单项选择题 Which EPIRB transmits a distress alert that is received and relayed by an INMARSAT satellite?（）
单项选择题 Which condition represents the appropriate time for setting off distress flares and rockets? （）
