The main function of the respiratory system is to allow the exchange of gases between the atmosphere and the lungs.
Hence,the only structure that carries out this function is the alveoli as other structures such as the nose,trachea and pharynx transport gases to the alveoli just so that it can can out its function.
Veins carry blood from the body to the heart.
Arteries carry blood from the heart to the body.
Your answer is: arteries
Hope that helped:)
Both help the planet but algae can do it way faster.
Living things must have a metabolism in order to be considered living.
B. They are used for display, in combat and in defense against enemies.
