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Author Question: A 20-foot-tall tree that seemed to have stopped growing was cut down by the forester who was ... (Read 193 times) |
Human neurons are so small that they require a microscope in order to be seen. However, some neurons can be up to 3 feet long, such as those that extend from the spinal cord to the toes.
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
Computer programs are available that crosscheck a new drug's possible trade name with all other trade names currently available. These programs detect dangerous similarities between names and alert the manufacturer of the drug.
The familiar sounds of your heart are made by the heart's valves as they open and close.
Dogs have been used in studies to detect various cancers in human subjects. They have been trained to sniff breath samples from humans that were collected by having them breathe into special tubes. These people included 55 lung cancer patients, 31 breast cancer patients, and 83 cancer-free patients. The dogs detected 54 of the 55 lung cancer patients as having cancer, detected 28 of the 31 breast cancer patients, and gave only three false-positive results (detecting cancer in people who didn't have it).