| A | B |
|---|
| The largest land areas on Earth | continent |
| half of theEarth | hemisphere |
| a resource that can be replaced | renewable resource |
| a resource that cannot be replaced | nonrenewable resource |
| a small river that flow into a larger river | tributary |
| materials in the environment that people need | natural resource |
| poison used to kill insects | pesticides |
| Materials like oil made from long dead plants and animals | fossil fuels |
| environmental conditions over a long period of time | climate |
| the most important part of something | keystone |
