Across
- 7. a form of oxygen, O 3 , with a peculiar odor suggesting that of weak chlorine, produced when an electric spark or ultraviolet light is passed through air or oxygen. It is found in the atmosphere in minute quantities, especially after a thunderstorm, is a powerful oxidizing agent, and is thus biologically corrosive. In the upper atmosphere, it absorbs ultraviolet rays, thereby preventing them from reaching the surface of the earth. It is used for bleaching, sterilizing water, etc.
- 8. natural no growth hormones
- 9. capable of being sustained
- 13. able to be renewed
- 16. the act of emitting
- 17. to treat or process (used or waste materials) so as to make suitable for reuse
- 18. objects strewn or scattered about; scattered rubbish
- 19. no longer existing
Down
- 1. mixture of various decaying organic substances, as dead leaves or manure, used for fertilizing soil.
- 2. to keep safe from injury, harm, or destruction
- 3. a system formed by the interaction of a community of organisms with their environment
- 4. a system of trash and garbage disposal in which the waste is buried between layers of earth to build up low-lying land
- 5. to keep in a safe or sound state
- 6. the natural environment of an organism; place that is natural for the life and growth of an organism
- 10. the gaseous envelope surrounding the earth
- 11. the area of which you are surrounded
- 12. proceeding from the sun, as light or heat
- 14. to process (used goods or waste material) so as to produce something that is often better than the original
- 15. the act of making dirty
- 19. the branch of biology dealing with the relations and interactions between organisms and their environment, including other organisms