【单项选择题】
PAN-PAN repeated three times over the radiotelephone indicates which type of message will follow?().
A、A.Distress
B、B.Safety
C、C.All clear
D、D.Urgency
A、A.Distress
B、B.Safety
C、C.All clear
D、D.Urgency
A、A.securite repeated 3 times B、B.safety repeated 3 times C、C.pan pan repeated 3 times D、D.securite securite repeated 3 times