Answer:
Option C. The lungs.
Explanation:
Alveolis are the air sacs in the lungs which main function is to get oxygen into your bloodstream and carbon dioxide leaves the blood.
The alveolis are located in the lungs, and it's where the respiratory and circulatory systems meet, for the reasons stated before.
Therefore, the correct option is Option C.
This is because of natural selection; since polar bears live in a rough environment, natural selection gives them more fur, more muscle, and can go longer without food
Carbohydrates= Saccharides or simple sugars
Protein= Amino Acid
It uses nephridium as the expiratory organ for flat worms
For number 3: helps the body digest food.
good bacteria can help treat some bacterial infections.
without bacteria you wouldn't exist.
bacteria produces vitamin k.
