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It is difficult to obtain enough calcium without consuming milk or other dairy foods.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.
Blood is approximately twice as thick as water because of the cells and other components found in it.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
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