| A | B |
|---|
| biomass | another word for living matter |
| wind energy | caused by uneven heating and cooling of Earth |
| solar energy | the source of energy for all plants and animals |
| water energy | this energy is created only if the source is fast moving |
| electricity | movement of positive and negative atoms |
| oil | ancient sea organisms formed this |
| coal | dead remains of ancient plants |
| geothermal | underground heat |
| natural gas | nonrenewable but cleaner than oil or coal |
| energy | the ability to do work |
| force | a push or pull on an object |
