Across
- 3. natural resource that can be replenished in a short time
- 5. how we obtain our fossil fuels
- 6. materials in the environment that are useful to people
- 9. consumption of sand has caused river pollution, ______, and droughts
- 13. energy produced by the heat within the Earth
- 14. coal, natural gas, petroleum are examples of
- 15. fracking poses a threat to what natural resource
- 16. alternative energy that uses falling water
- 18. an increase in green house gases affects Earth's _________
- 19. another word for petroleum
Down
- 1. renewable resources do not cause _______
- 2. a method of extracting resources through drilling and water pressure
- 4. a resource that cannot be easily replaced
- 7. energy from the sun
- 8. energy from living or once-living things
- 10. coal is considered a ___________ resource
- 11. solar energy is ________
- 12. natural ingredient used to make concrete, asphalt, and glass
- 17. fossil fuels are more popular because they're _______