| A | B |
|---|
| rift | a deep crack in the earth's surface |
| plateau | high, flat land that is higher than the surrounding land |
| elevation | height of land above sea level |
| fertile | rich in the substances that plants need to grow well |
| tributary | a river that flows into a larger river |
| savanna | a region of tall grasses with scattered trees |
| drought | a long period without rain |
| oasis | fertile place in a desert where there is water |
| nomad | a person who has no permanent home |
| irrigate | to supply with water |
| cacao | the tree from which chocolate comes from |
| malaria | disease spread from the bite of an infected mosquito. |
| subsistence farming | raising just enough crops to feed one's family |
| cash crop | a crop that is grown for sale |
| economy | a system for producing ,,distributing and consuming goods and sevices |
| diversify | to add variety to or to expand a country's economy |
