The term “radar contact” _______ .
A.is used by ATC
B.is used by the pilot
C.means the aircraft has been radar identified
D.both A and C
正确答案是D
The term “radar contact” _______ .
A.is used by ATC
B.is used by the pilot
C.means the aircraft has been radar identified
D.both A and C
正确答案是D