| A | B |
|---|
| plateau | A large, level area that rises above the surrounding land; has at least one side with a steep slope. |
| elevation | The height of land above or below sea level. |
| rift | A deep crack in Earth's surface. |
| tributary | A river or stream that flows into a larger river. |
| fertile | Rich in the substances plants need to grow well. |
| irrigate | To supply with water through a ditch, pipe, channel, or sprinkler. |
| drought | A long period of little or no rain fall. |
| oasis | A fertile place in a desert where there is water and vegetation. |
| savanna | A region of tall grasses with scattered trees. |
| nomad | A person who has no permanent, settled home and who instead moves form place to place. |
| subsistence farming | Raising just enough crops to support one's family. |
| cash crop | A crop that is raised for sale. |
| economy | A system for producing, distributing, consuming, and owning goods and services. |
| diversify | To add variety to; to expand a country's economy by increasing the variety of goods produced. |
