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The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.
About 600,000 particles of skin are shed every hour by each human. If you live to age 70 years, you have shed 105 pounds of dead skin.
Your heart beats over 36 million times a year.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
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