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Did you know?

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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Multiple sclerosis is a condition wherein the body's nervous system is weakened by an autoimmune reaction that attacks the myelin sheaths of neurons.

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In 1844, Charles Goodyear obtained the first patent for a rubber condom.

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Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.

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Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.

Upper Paleolithic stone tools include blade-based tools as seen here being produced from a blade cor Upper Paleolithic stone tools include blade-based tools as seen here being produced from a blade cor
A levallois core from Kapedo Tuffs, Kenya dates about 130,000 years ago. A levallois core from Kapedo Tuffs, Kenya dates about 130,000 years ago.
A Diagrammatic Representation of the James-Lange Theory of Emotion A Diagrammatic Representation of the James-Lange Theory of Emotion
Structure of the nucleosome core particle as revealed by X-ray diffraction Structure of the nucleosome core particle as revealed by X-ray diffraction
Acetylation of core histones Acetylation of core histones
Bacterial RNA polymerase core plus a sigma Bacterial RNA polymerase core plus a sigma
Video: Green alga life cycle Animation

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