| A | B |
|---|
| natural resource | A naturally occurring material that is valuable to and used by humans. |
| extinct | Refers to species that are no longer existing. |
| endangered species | A species that may soon become extinct. |
| birthrate | the rate at which members are born into a population. |
| death rate | Rate at which members of a population die. |
| conservation | The preservation and wise use of natural resources. |
| fossil fuel | An energy source that is the product of plants and animals that once lived on the earth. |
| pollution | the addition of pollutants to an ecosystem. |
| biodegradable pollutant | A pollutant that is capable of being broken down by the environment. |
| nonbiodegradable pollutant | A pollutant that cannot be broken down by living organisms |
| trash | Solid material that is useless or unwanted. |
| sanitary landfill | A trash dump over which a layer of dirt is spread periodically. |
| recycle | To use again |
