Across
- 1. strong, unpleasant and sometimes dangerous smoke that leaves vehicles and factories
- 3. (two words) (to ____) to increase knowledge about a topic
- 4. (to _____) throwing rubbish in places you shouldn't
- 6. (two words) something natural that can be replaced as fast as it is consumed
- 8. (two words) the system of animals eating other animals and plants
- 10. all the animals and plants that live in an area
- 11. (noun) when there is very little of something
- 12. something that can be maintained into the future
Down
- 2. a product or process that doesn't harm nature
- 5. (adjective) when something is rare or hard to find
- 7. another word for dangerous
- 9. (to ____) to do well and grow in an environment
- 13. air pollution caused by smoke and fumes