C. Protective over young cubs
Absorbing CO2 into the blood is a part of the respiratory system!
Rain and snow will occur in low air pressure.
When the pressure of the air is low, the air rise upward in the atmosphere and gets cool and condenses. The condensation causes the formation of clouds from water droplets and snow particle around the dust particle in the sky and at last the the condensation of water vapor causes the formation of rain.
