The official airport elevation is the highest part of the usable _______ measured in feet above mean sea level.
A.airport
B.runway
C.apron
D.taxiway
正确答案是B
The official airport elevation is the highest part of the usable _______ measured in feet above mean sea level.
A.airport
B.runway
C.apron
D.taxiway
正确答案是B