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The familiar sounds of your heart are made by the heart's valves as they open and close.
In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.
There are approximately 3 million unintended pregnancies in the United States each year.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
Signs and symptoms of a drug overdose include losing consciousness, fever or sweating, breathing problems, abnormal pulse, and changes in skin color.
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