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Author Question: The significant causes of health burdens in the United States have been evolving. As described in ... (Read 193 times) |
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.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
The horizontal fraction bar was introduced by the Arabs.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.