Explain how oxygen and carbon dioxide are transported in our body.

ANSWER
i) Oxygen enters the blood from the lungs and carbon dioxide is expelled out of the blood into the lungs.
ii) The blood serves to transport both gases.
iii) Oxygen is carried to the cells.
iv) Carbon dioxide is carried away from the cells.

Depression is lifelong, though you can get medication to with it. the difference between sadness and depression is that sadness lasts a little bit, depression last a long time and it goes on and off. people usually get depression through experiences they have been through, or genetics.