The purpose of the oxygen system is to provide _____ for the flight crew and passengers when required.
A.oxygen;;
B.fuel;
C.oil
D.conditioned air;
正确答案是A
The purpose of the oxygen system is to provide _____ for the flight crew and passengers when required.
A.oxygen;;
B.fuel;
C.oil
D.conditioned air;
正确答案是A