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Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.

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The immune system needs 9.5 hours of sleep in total darkness to recharge completely.

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In the ancient and medieval periods, dysentery killed about ? of all babies before they reach 12 months of age. The disease was transferred through contaminated drinking water, because there was no way to adequately dispose of sewage, which contaminated the water.

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The term bacteria was devised in the 19th century by German biologist Ferdinand Cohn. He based it on the Greek word "bakterion" meaning a small rod or staff. Cohn is considered to be the father of modern bacteriology.

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Anesthesia awareness is a potentially disturbing adverse effect wherein patients who have been paralyzed with muscle relaxants may awaken. They may be aware of their surroundings but unable to communicate or move. Neurologic monitoring equipment that helps to more closely check the patient's anesthesia stages is now available to avoid the occurrence of anesthesia awareness.

Blood-typing and cross-reactions: The blood type depends on the presence of surface antigens (agglut Blood-typing and cross-reactions: The blood type depends on the presence of surface antigens (agglut
In 2008, the U.S. economy suffered a gaping wound as several trillion dollars were ripped out of it. In 2008, the U.S. economy suffered a gaping wound as several trillion dollars were ripped out of it.
In the summer of 1793, a yellow fever epidemic struck Philadelphia, killing nearly 4,000. Tens of th In the summer of 1793, a yellow fever epidemic struck Philadelphia, killing nearly 4,000. Tens of th
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Video: Fetal Development of the Cardiovascular System

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