The flight altitude for aircraft with no oxygen equipment or whose oxygen equipment is unserviceable should not exceed _______ meters.
A.3600
B.4000
C.4500
D.5000
正确答案是B
The flight altitude for aircraft with no oxygen equipment or whose oxygen equipment is unserviceable should not exceed _______ meters.
A.3600
B.4000
C.4500
D.5000
正确答案是B