| A | B |
|---|
| plateau | large raised areas of mostly level land |
| elevation | the height of land above sea level |
| escarpment | steep cliff |
| cataracts | rock-filled rapids |
| silt | tiny bits of rocks and dirt that build up on the bottoms of rivers and lakes |
| fertile | containing substances that plants need in order to grow well |
| tributaries | small rivers and streams that flow into a larger river |
| irrigate | to artificially water |
| oasis | a place where springs and fresh underground water make it possible to support life in a region that gets little rain |
| savanna | a region of tall grasses |
| nomads | people who move around to various places to make a living |
| subsistence farming | to raise crops to support their families and animals |
| cash crop | a crop that is raised for sale |
| economy | a system for producing, distributing, consuming, and owning goods, services, and wealth |
| diversify | to add variety |
| Mali | The Mali Empire or Mandingo Empire or Manden Kurufaba[4] was a West African empire of the Mandinka from c. 1230 to c. 1600. The empire was founded by Sundiata Keita and became renowned for the wealth of its rulers, especially Mansa Musa I. |
| Mansa Musa | Mansa Musa, was the tenth mansa, which translates as "king of kings" or "emperor", of the Malian Empire. |
| Songhai | The Songhai Empire, also known as the Songhay Empire, was a state located in western Africa. From the early 15th to the late 16th century, Songhai was one of the largest Islamic empires in history. |
| griot | West aftican storyteller |
| Lalibela | Lalibela is one of Ethiopia's holiest cities, second only to Aksum, and is a center of pilgrimage for much of the country. |
