| A | B |
|---|
| Fresh water | not salty |
| Ocean water | 3/4 of earth's surface covered with water |
| Air pressure | decreases or is lower as you go up (Like at the top of a mountain) |
| Baltic Sea | less salty because many rivers flow into it |
| Air | is the gases that surround the earth |
| Air moves | toward the area of low pressure |
| Barometer | measures air pressure |
| Humidity | the amount of water in the air |
| Stratus clouds | flat layers that form close to earth's surface, may bring rain or snow |
| Condensation | water vapor becoming liquid water as it cools |
| Curving lines | show fronts and how they are moving |
| Water Cycle | Hot sun warms the earth. The heat causes water to evaporate; the water vapor rises into the sky and meets cold air. It condenses into water droplets, Millions of drops come together to make clouds. When a cloud gets full of water, water drops |
| Greenhouse gases | can be beneficial, keep earth warm |
| Cumulus clouds | thick, white puffy, appear in good/fair weather |
| Cirrus clouds | feathery, form high in the atmosphere where the water vapor turns to ice crystals |
| Cold front | has clouds along it because water vapor in warm air cools and condenses into clouds |
