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Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
If all the neurons in the human body were lined up, they would stretch more than 600 miles.
Many medications that are used to treat infertility are injected subcutaneously. This is easy to do using the anterior abdomen as the site of injection but avoiding the area directly around the belly button.
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.
Your heart beats over 36 million times a year.