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There are approximately 3 million unintended pregnancies in the United States each year.
The lipid bilayer is made of phospholipids. They are arranged in a double layer because one of their ends is attracted to water while the other is repelled by water.
On average, someone in the United States has a stroke about every 40 seconds. This is about 795,000 people per year.
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.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.