问题
单项选择题
Messages concerning weather conditions transmitted by radiotelephone are preceded by().
A.MAYDAY
B.PAN-PAN
C.SECURITE
D.SOS
答案
参考答案:C
Messages concerning weather conditions transmitted by radiotelephone are preceded by().
A.MAYDAY
B.PAN-PAN
C.SECURITE
D.SOS
参考答案:C