Aerial Refueling is a procedure used by the _______ to transfer fuel from one aircraft to another during flight.
A.CAAC
B.airliners
C.general aviation
D.military
正确答案是D
Aerial Refueling is a procedure used by the _______ to transfer fuel from one aircraft to another during flight.
A.CAAC
B.airliners
C.general aviation
D.military
正确答案是D