Radar because the waves are reflected back off of the source so with the reflection it's hard for them to see earth surface.
Answer:
This area has been hit by an asteroid, and the land now has a giant hole in it.
Explanation:
a region that is made up of different places that are linked and function as a unit
A, in urban areas :)
Urban areas have bigger populations than rural ones and the Rocky Mountains have terrain that is difficult to settle on
