Codes shall be assigned to aircraft in accordance with the plan and procedures laid down by the appropriate _______ authority.
A.ATC
B.ATS
C.AIS
D.SAR
正确答案是B
Codes shall be assigned to aircraft in accordance with the plan and procedures laid down by the appropriate _______ authority.
A.ATC
B.ATS
C.AIS
D.SAR
正确答案是B