C. Xylem moves water up, and phloem moves food down
Answer:
the discoveries, events and people that continue to affect the history ... The extremely infectious disease was class-blind, killing rich and ... that a few cells remaining in Petri dishes could be used as biological weaponry. ... smallpox, a disease that had now been killing unhindered for at least 2,800 years.
Explanation:
The answer is <em>A.) You have antibodies that already recognize the virus</em>
Viruses and diseases are always changing. When we get sick with say the flu, a virus, or the cold of sorts, our body attacks it until it fights off the disease. You can't get sick from the same strand of sickness because once your body defeats the virus, it knows how to protect the body from it because of the antibodies, so the virus ends up evolving to get past your immune system again.
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Answer: I believe the answer you're looking for is Adenine goes with Thymine and Cystosine goes with Guanine.
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