Low pressure!
It tends to go from high to low in air pressure! (: If you didn't know - atmospheric pressure can be determined by something called a mercurial barometer! I hope all is well, and you pass! Good luck, rockstar! (:
Let me know if you have any questions, or any comments! (:
The answer is A natural boundary
Overgrazing results when too many animals graze, eating the grass faster than it can grow.
