Answer:
Yes it is helpful
Explanation:
Not only do we live in harmony with these beneficial bacteria, but they are actually essential to our survival. Good bacteria help our bodies digest food and absorb nutrients, and they produce several vitamins in the intestinal tract — including folic acid, niacin, and vitamins B6 and B12.
Gas exchange of oxygen and carbon dioxide takes place in the alveoli<span>. Oxygen from the inhaled air diffuses through the walls of the </span>alveoli<span> and adjacent capillaries into the red blood cells. The oxygen is then carried by the blood to the body tissues.</span>
Multicellular .................................
