| A | B |
|---|
| continent | One of earth's largest land areas |
| limestone | Natural resources used to make cement |
| keystone | Supports the other stones in an arch |
| tributary | A small river or stream that flows into a larger river |
| pesticides | Chemicals used for killing insects |
| Ohio | State that shares PA's western border |
| sandstone | Resource used to make glass |
| natural resources | materials found in nature that people can use |
| Northern/Western | PA is located in these hemispheres |
| elevation | The height of land |
| precipitation | Rain, sleet, and snow are examples of this |
| climate | The pattern of weather in a place over a long period of time |
| North America | PA is located on this continent |
| pollution | Anything that makes water, air, or soil dirty |
| landform | A natural feature on the Earth's surface |
| habitat | Theplace where animals or plants live |
| Allegheny Mountains | Crosses the middle of PA from the southwest to the northeast |
| Car exhaust | Not a source of water pollution |
