The correct answer is C
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Answer:haemoglobin
Explanation:
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.
Answer:
a point in time, event, or experience when one has a sudden insight or realization:
<span>So that the cells can function correctly. </span>