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There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Elderly adults are living longer, and causes of death are shifting. At the same time, autopsy rates are at or near their lowest in history.
The ratio of hydrogen atoms to oxygen in water (H2O) is 2:1.
Everyone has one nostril that is larger than the other.
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