Environment

5. The geological process in which earthen materials are worn away and transported by natural forces such as wind or water.
6. The process of wearing or being worn by long exposure to the atmosphere
7. The natural process of recycling organic matter, such as leaves and food scraps, into a valuable fertilizer that can enrich soil and plants.
9. The layer of the earth's atmosphere above the troposphere.

1. A giant woody grass that is grown chiefly in the tropics.
2. A substance that pollutes something, especially water or the atmosphere.
3. An interaction between two different organisms living in close physical association, typically to the advantage of both.
4. A natural resource or source of energy that is not depleted by use, such as water, wind, or solar power.
8. The plants of a particular region, habitat, or geological period.