| A | B |
|---|
| natural resource | anything found in nature that is useful to people |
| nonrenewable resource | resource that cannot be replaced easily |
| fossil fuels | energy resources formed from the remains of plants and animals that died millions of years ago |
| renewable resource | resources that can be replaced as they are used |
| solar energy | energy from the sun |
| hydroelectric energy | energy from moving water |
| wind energy | energy of moving air |
| geothermal energy | heat energy from inside Earth |
| biofuel | fuel made from living things |
| magma | melted rock that is underground |
| lava | melted rock on the surface of the Earth |
| igneous rocks | rocks that formed from cooled magma or lave |
| sedimentary rocks | rocks that formed from sediments that are pressed and cemented together |
| metamorphic rocks | rocks that formed from existing rocks that have been squeezed and heated deep inside Earth's crust |
