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Author Question: Bell Telephone Laboratories invented the ________, which replaced the vacuum tube. (Read 246 times) |
The familiar sounds of your heart are made by the heart's valves as they open and close.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Chronic necrotizing aspergillosis has a slowly progressive process that, unlike invasive aspergillosis, does not spread to other organ systems or the blood vessels. It most often affects middle-aged and elderly individuals, spreading to surrounding tissue in the lungs. The disease often does not respond to conventionally successful treatments, and requires individualized therapies in order to keep it from becoming life-threatening.
The average office desk has 400 times more bacteria on it than a toilet.
It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.