Fact 1: High pressure systems cause clear weather.

Fact 2: High pressure means falling air, which is a condition minimizing cloud formation.

Given the two facts above, answer the question "what does low pressure weather cause?" with the following options: 
- Pollution
 - flooding
 - friction
 - clear air
 - contamination
 - Dehydration
 - rainfall
 - relocation


 

    clear air     