Question

It is difficult to breathe at high places. Why?
a) Due to cold, air freezes.
b) Air is at low pressure and contains less oxygen
c) Nose has to work harder to breathe.​

Answer 1

Answer:

b) Air is at low pressure and contains less oxygen

Explanation:

The air at higher altitudes is colder, less dense, and contains fewer oxygen molecules. This means that you need to take more breaths in order to get the same amount of oxygen as you would at lower altitudes. The higher the elevation, the more difficult breathing becomes.

Answer 2

Answer:

b

Explanation:

as altitude increases the layers of air becomes thin . Tat is the reason why mountaineers carry oxygen cylinders with them when they climb mountains