| A | B |
|---|
| Global Positioning System (GPS) | a group of satellites traveling around Earth |
| environment | natural surroundings |
| geography | the study of the earth in all of its variety |
| landforms | individual features of the land |
| regions | areas that share some common characteristics |
| orbit | a planet's path around the sun |
| solstice | the first day of summer and of winter |
| the solar system | the sun, planets and other smaller bodies |
| a revolution | the earth's complete trip around the sun |
| equinox | when day and night of are equal length in both hemispheres |
| faults | cracks in the earth's crust |
| core | the center part of the earth |
| plate tectonics | the theory about the earth's structure |
| continents | massive land areas |
| mantle | the thick layer of rock around the earth's core |
| source | point at which a river originates |
| continental shelf | an underwater plateau |
| elevation | height above sea level |
| peninsula | piece of land surrounded by water on three sides |
| oceans | the earth's largest bodies of water |
