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Quiz on Oxygen and Carbon Dioxide in Human Physiology
Quiz on Oxygen and Carbon Dioxide in Human Physiology
Quiz
Question 1
Question 2
Question 3
Question 4
Question 5
Question 6
Question 7
Question 8
Restart
What percentage of the air we breathe is composed of oxygen (O2)?
A.
98%
B.
21%
C.
2%
D.
75%
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