Did you know?

Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.

Did you know?

There are over 65,000 known species of protozoa. About 10,000 species are parasitic.

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This year, an estimated 1.4 million Americans will have a new or recurrent heart attack.

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Blood is approximately twice as thick as water because of the cells and other components found in it.

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Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.

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