The mission of undertaking special flights is made known by _______ according to instructions from higher-ups.
A.air force
B.regional ATMB
C.CAAC
D.ATMB of CAAC
正确答案是C
The mission of undertaking special flights is made known by _______ according to instructions from higher-ups.
A.air force
B.regional ATMB
C.CAAC
D.ATMB of CAAC
正确答案是C