Across
- 4. age when fossil fuels formed
- 6. energy/originates from the rise and fall of Earth's ocean
- 7. over the world
- 10. it originates inside the earth, and it is free
- 11. is the top consumer of petroleum
- 12. synonym of "not enough"
Down
- 1. country exports oil
- 2. buys almost all the petroleum it needs
- 3. of this metal in Bolivia
- 5. helps to conserve nonrenewable resources
- 8. you use too much of it
- 9. it is used to manufacture aluminum