Mainly because our lungs are made to intake air, and if we where to inhale water we would drown. oxygen can only be obtained from the air because our lungs would be able to expell the excess stuff from air easier than in water. hope i helped.
B 5 years it takes 5 years before symptoms to appear
Have a primitive digestive system
This process, called lipolysis, takes place in the cytoplasm. The resulting fatty acids are oxidized by β-oxidation into acetyl CoA, which is used by the Krebs cycle.
