Across
- 2. coal,petroleum are
- 3. a factor that encourages people
- 4. residential area on the edge of a city
- 6. the development of machine powered production
- 8. water, soil
- 9. a network of living things that depend on each other to survive
- 10. a useful material found in the environment
- 11. waste that makes the air,soil, water less clean
- 12. limited quantities
- 13. pollution
Down
- 1. the loss of forest cover in aregion
- 5. variety of living things in an ecosystem
- 7. reource that cannot be replaced in a short time