An airplane is in a clean configuration when the _______ .
A.gear and ailerons are down
B.flaps and ailerons are up
C.gear and flaps are down
D.gear and flaps are up
正确答案是D
An airplane is in a clean configuration when the _______ .
A.gear and ailerons are down
B.flaps and ailerons are up
C.gear and flaps are down
D.gear and flaps are up
正确答案是D