Environmental puzzle
Across
- 2. wind solar etc.
- 8. energy in a transformed state
- 9. can be replenished
- 10. remains of ancient organisms that with time and pressure will transform into coal, oil or natural gas
- 11. used oil energy a 70% on 2016
- 12. in US is made 30% of coal
Down
- 1. the ability to do work
- 3. source that will eventually run out
- 4. 80% of world energy
- 5. forms that can be used directly as they appear in nature
- 6. 20% of total energy sources
- 7. a solid combustible mineral made of carbon, formed with organic matter after millions of years of compression