Because they are not man made and are part of the earth's natural features caused by the the weathering and erosion of the earth.
I think it's true. I may be wrong. Sorry if i am
These four subsystems are called "spheres." Specifically, they are the "lithosphere" (land), "hydrosphere" (water), "biosphere" (living things), and "atmosphere" (air). Each of these four spheres can be further divided into sub-spheres
Either the first one or second one
The Answer is second option (Tombouctou).
