The radio call to alert ground personnel when an A/C is having difficulty, but is in no immediate danger, is _______.
A.MAYDAY MAYDAY MAYDAY
B.HELP HELP HELP
C.PANPAN PANPAN PANPAN
D.SOS SOS SOS
正确答案是C
The radio call to alert ground personnel when an A/C is having difficulty, but is in no immediate danger, is _______.
A.MAYDAY MAYDAY MAYDAY
B.HELP HELP HELP
C.PANPAN PANPAN PANPAN
D.SOS SOS SOS
正确答案是C