Answer:
its circadian rhythm coordinated by pineal gland through melatonin hormone that it produces!!
Sometimes infections r in u a while but viruses r like in you body traviling
I think it’s the second option :)
Answer:
Capillaries
Explanation:
Capillaries connect the arteries to veins. The arteries deliver the oxygen-rich blood to the capillaries, where the actual exchange of oxygen and carbon dioxide occurs. The capillaries then deliver the waste-rich blood to the veins for transport back to the lungs and heart. Veins carry the blood back to the heart.
