Blood turns red when we start bleeding because the chemical composition of our blood changes when it reaches the air. This is known as oxidation, and no, it is probably not okay if your blood doesn't turn red once it reaches the outside of your body.
<span>Purines and pyrimidines form hydrogen bonds between each other. Certain polar chemical groups form electrostatic interactions or hydrogen bonds. The A-T and C-G pairings form the hydrogen bonds between the amine and carbonyl groups on the complementary bases.</span>
The answer is: [D]: "os" .
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The opening for the "cervical canal" is called the:
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→ "cervical os" .
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Note that: "os" — means "mouth" in Latin; which is similar to "opening' .
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