Answer:
carbon dioxide passes from the blood into the alveoli and is then exhaled. Oxygenated blood travels from the lungs through the pulmonary veins and the cycle goes on every time you breath or inhale you inhale oxygen into your blood cells.
Explanation:
Answer:
yes, even though they are still intact they can sill build up bacteria/germs.
Explanation:
Hope this helps!
That something is wrong with them and they are not doing the best since their oxygen level is low
