MCQOPTIONS
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MCQOPTIONS
| 1. |
The 'isotope' carbon-12 makes up about |
| A. | 90% of carbon on earth |
| B. | 80% of carbon on earth |
| C. | 99% of carbon on earth |
| D. | 89% of carbon on earth |
| Answer» D. 89% of carbon on earth | |