Earth Day

3. Trash, such as paper, cans, and bottles, that is left lying in an open or public place.
4. make smaller or less in amount, degree, or size.
9. contaminate (water, air, or a place) with harmful or poisonous substances.
11. no longer in existence.
13. a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants.
14. relating to or derived from living matter.
15. (of a contract, agreement, etc.) capable of being renewed.

1. A biological community of interacting organisms and their physical environment.
2. convert (waste) into reusable material.
5. Decayed organic material used as a plant fertilizer.
6. Relating to or determined by the sun.
7. a colorless unstable toxic gas with a pungent odor and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light. It differs from normal oxygen (O2) in having three atoms in its molecule (O3).
8. The envelope of gases surrounding the earth or another planet.
10. a place to dispose of refuse and other waste material by burying it and covering it over with soil, especially as a method of filling in or extending usable land.
12. the production and discharge of something, especially gas or radiation.