| A | B |
|---|
| plateau | a large, level area that rises aboe the surrounding land; has at least one side with a steep slope. |
| elevation | the height of land above or below sea level. |
| drought | a long period of little or no rain. |
| rift | a deep crack in the Earth's surface. |
| fertile | rich in the substances plants need to grow well. |
| tributary | a river or stream that flows into a larger river. |
| irrigate | to supply with water through a ditch, pipe, channel, or sprinkler. |
| 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 instead moves from place to place. |
| subsistence farming | raising just enough crops to support ones 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 expand a country's economy by increasing the vareity of goods produced. |
