| A | B |
|---|
| oxygen | a gas that animals need to live |
| carbon dioxide | a gas plants need to make food |
| conservation | to save or protect something without wasting it |
| pollution | harmful substances have been added to our soil, water or air |
| erosion | the washing away of soil by water |
| recycle | to process and reuse materials such as glass, plastic and aluminum |
| interdependency | when one living things depends on another living thing to survive |
| energy | the ability to do work |
| solar energy | energy from the Sun |
| fossil fuels | fuels that were formed underground over millions of years |
| renewable energy resources | a resource that can be replaced in our lifetime |
| nonrenewable energy resources | sources of energy that cannot be replaced in our lifetime |
| natural resource | something that comes from nature that is useful to people |
| coal, oil, natural gas | the three fossil fuels |
| wind energy | energy that comes from moving air |
| water energy | energy that comes from fast moving water |
