Answer:
The reason is because Flagstaff is at a higher elevation than Phoenix.
Explanation:
The air is thinner at higher elevations. You can google Flagstaff's elevation compared to Phoenix but the simple answer is that air is thinner at higher elevations and some people used to 'thicker' air find it harder to breath, especially after some strenuous exercise.
It creates oxygen which every living thing needs to live. i hope this helps! :)
Answer:
the pressure would be 0.9 atmospheres
Explanation:
you just gotta add the presures for each of the gases that are added
