MCQOPTIONS
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| 1. |
Q: The approximate percentages of oxygen, nitrogen, and carbon dioxide in pure air on the Earth's atmosphere are: |
| A. | 0.03%, 21% and 78% respectively |
| B. | 78%, 21% and 0.03% respectively |
| C. | 21%, 78% and 0.03% respectively |
| D. | 21%, 7.8% and 0.03% respectively |
| Answer» D. 21%, 7.8% and 0.03% respectively | |