Across
- 4. the total amount of organisms in a given area.
- 7. a company authorized to act as a single entity.
- 8. the ability to do something or produce something without waste.
- 9. energy produced by the internal heat of the earth.
- 11. money that can be offset against a liability.
- 12. natural movement of air along the ground.
Down
- 1. clean energy produced by shifting water in ocean tides.
- 2. of or relating to the sun.
- 3. a substance which expands freely to fill any space available.
- 5. a thing that motivates or encourages one to do something.
- 6. denoting the generation of power using flowing water.
- 10. a system of garbage and trash disposal in which waste is buried between layers of earth.
- 11. a tax or duty to be paid on a particular class of imports or exports.