D.
Small particles of rock are carried by wind over an area. The particles start to accumulate making hills of sand.
Let me know if I’m wrong!
Non-ecumene means regions of the world that are uninhabited or very sparsely populated. Usually the regions of the world that are ecumenic and non-ecumenic are hard to draw as many regions which are densely populated merge with sparsely populated regions and the boundaries that they do share are not static, as they can change with time and movement of people.
Answer:
This region is called the mantle. it's the movement of matter that results from differences in density caused by variations in temperature
UHhHh, not enough context. Density = mass/volume.