| A | B |
|---|
| longitude | The curving distance east or west of the prime meridian that stretches from the North Pole to the South Pole. |
| migration | The mass movement of people from one area to another. |
| natural resources | Various materials found in nature used in manufacturing such as wood, coal, and oil. |
| ozone layer | The layer of the upper atmosphere where ozone collects. This layer absorbs harmful ultraviolet radiation from the Sun. |
| Panama Canal | A canal that crosses the isthmus of Panama connecting the Atlantic and Pacific Oceans. Built by the United States between 1904 and 1914. |
| pesticides | Chemicals used to destroy insects and other pests. |
| resources | An asset that is beneficial to a country or people. |
| river | A moving body of water that usually has its source in an area of high ground |
| river delta | The end of a river where rich deposits of silt build up. This is important to human habitation due to the excellent source of good farmland. |
| river valley | A valley that is carved out by the river. Often have fertile land, and are the sites for the earliest civilizations. |
| Sahara Desert | The world’s largest desert, located in North Africa. |
| silt | Very fine grains of dirt deposited by a moving body of water. |
| terrace farming | The cutting out of flat areas (terraces) into near vertical slopes to allow farming. Terrace farms appears as steps cut into a mountainside. This adaptation allowed both the early Chinese, and the Inca of Mesoamerica to grow enough food for their large populations. |
| Three Gorges Dam | A dam across the Yangtze River in China scheduled to be completed in 2009. |
