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Author Question: Mr. Turnbull needs to speak to his class about library books that are missing from the class ... (Read 434 times) |
The familiar sounds of your heart are made by the heart's valves as they open and close.
In 1864, the first barbiturate (barbituric acid) was synthesized.
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.
Calcitonin is a naturally occurring hormone. In women who are at least 5 years beyond menopause, it slows bone loss and increases spinal bone density.
Blood is approximately twice as thick as water because of the cells and other components found in it.