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Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
The familiar sounds of your heart are made by the heart's valves as they open and close.
After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.
Most women experience menopause in their 50s. However, in 1994, an Italian woman gave birth to a baby boy when she was 61 years old.
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