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Did you know?
The horizontal fraction bar was introduced by the Arabs.
Did you know?
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Did you know?
The familiar sounds of your heart are made by the heart's valves as they open and close.
Did you know?
Symptoms of kidney problems include a loss of appetite, back pain (which may be sudden and intense), chills, abdominal pain, fluid retention, nausea, the urge to urinate, vomiting, and fever.
Did you know?
Interferon was scarce and expensive until 1980, when the interferon gene was inserted into bacteria using recombinant DNA technology, allowing for mass cultivation and purification from bacterial cultures.