Answer:
Our breathing is affected in higher altitudes because of the air pressure being lower. Due to the air pressure being too low, we will not be able to breathe in enough oxygen, which is what affects our breathing. There are fewer oxygen molecules in the higher altitudes, so in order to get the same amount of oxygen as you normally would, you would need to take more breaths.
Step-by-step explanation:
hopefully this is enough! you're more than welcome to add onto it :)