Across
- 2. a colorless and odorless gas that people need to breath
- 5. something formed in the earth from plant or animal remains
- 6. to collect and treat used objects and materials that are ready to be thrown out in order to produce materials
- 8. animal life especially
- 9. the clear liquid that has no color, taste, or smell, that falls from clouds as rain
Down
- 1. The interacting system of a biological community and its non-living environmental surroundings.
- 3. the interaction between the physical surroundings around us
- 4. the plants occurring within a given region
- 7. chemical compound composed of one carbon and two oxygen atoms