“_______” is the height above the ground or water of the base of the lowest layer of cloud below 6000m covering more than half the sky.
A.Visibility
B.DDI
C.RVR
D.Ceiling
正确答案是D
“_______” is the height above the ground or water of the base of the lowest layer of cloud below 6000m covering more than half the sky.
A.Visibility
B.DDI
C.RVR
D.Ceiling
正确答案是D