| A | B |
|---|
| Thunderstorms don't last very long because | the cold fronts that cause them move very quickly. |
| Weather satellites send information to the National Weather Service instantly because | the weather changes constantly. |
| Flash floods are dangerous because | rising water in a river can wash away roads and cars. |
| Air masses move because | differences in air pressure and wind move them. |
| Weather all over the world can be tracked because | satellites above the Earth collect global information. |
| Fronts form because | warm and cold masses meet. |
| Standing under tall trees in a thunderstorm is dangerous because | they can be struck by lightning. |
| A warm air mass is pushed upward because | it is lighter than a cold air mass. |
| Meteorologists make weather predictions because | they study the weather. |
