The natural flow of rivers can be affected by several factors, such as building dams to provide drinking water, pumping of groundwater, climate change, and building of lands that change how natural water runs into surfaces and into rivers. All of these also disrupt the balance of ecosystem in the area.
Biological soil crusts<span> are communities of living organisms on the </span>soil<span> surface in arid and semi-arid ecosystems. They are found throughout the world with varying species composition and cover depending on topography, </span>soil<span> characteristics, climate, plant community, microhabitats, and disturbance regimes.</span>
It is called the seed coat
Each layer of earth has a different density the more in you go with the layers the more density is going to show up.
Crust-2.2g/cm^3
Upper mantle-3.4g/cm^3
Lower mantle-4.4g/cm^3
Outer core-9.9g/cm^3
Inner core-12.8g/cm^3
Hope I helped in something, Sorry if I didn't gave it my best shot:)
Answer:
air, oxygen, water, sand. and tea
