Hello!
A aquifer<span> names an underground area that collects and holds a large amount of water.
I know this because an aquifer collects water.
~ Hope I helped! ~
</span>
Answer:
Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body.
Explanation:
Hope this helps
These reactions are METABOLISM.