Environment

2. The whole mass of air that surrounds the Earth
5. A structure that looks like a bridge and that is used to carry water over a valley
6. Used to describe a type of animal or plant that has become very rare and that could die out completely
8. Relating to or using the natural heat produced inside the Earth
11. Using resources in a way that maintains their availability for future generations.
12. An underground layer of water-bearing rock or sediment.
14. Conversion of energy from sunlight into electricity (2 Words)
15. The clearing of trees from a forested area for other uses.

1. Decomposed organic material used as a natural fertilizer for plants.
3. Thick, soft, wet mud
4. To be slowly destroyed by natural processes
7. A science that deals with the relationships between groups of living things and their environments
9. A system in which waste materials are buried under the ground
10. The existence of many different kinds of plants and animals in an environment
13. A system formed by organisms in interaction with their environment.