As the two refracting surfaces AB and AC are not parallel to each other, the emergent ray is also not parallel to the incident ray. Whereas, in a glass slab, the two refracting surfaces are parallel to each other which ...

You must know that when we do exercise our body requires more energy. Due to exercise the body is able to get rid of excess carbon dioxide (CO₂). But remember, we get energy by the oxidation of food.