The danger area is centered at a point of N3219E11435 with a _______ of 30km.
A.range
B.radius
C.distance
D.circle
正确答案是B
The danger area is centered at a point of N3219E11435 with a _______ of 30km.
A.range
B.radius
C.distance
D.circle
正确答案是B