| A | B |
|---|
| Fold | bend in the rock layers |
| Fault | a break in the rock if the rocks on both sides have moved relative to one another |
| Mountains | exist because of movement along the tectonic plates |
| Folded mountains, fault-block mountains, and vocanoes | Three types of mountains |
| Plains | broad, flat areas that don't rise far about sea level |
| Plateaus | flat area uplifted more than 600m above sea level |
| Less than 3%` | of the Earth's water is fresh water |
| Ocean basin | covers about 30% of Earth's surface |
| Salinity | a measure of the amount of dissolved salts in a given amount of water |
| Fresh water | is frozen in ice sheets and glaciers so it is unavailable for human use |
| Water pollution | 2 biggest causes are industrailization and human population explosion |
