Another cause of sore throat is allergies that promote postnasal drip. There are, however, more serious conditions of the sinuses and throat that may cause the throat to be sore. If you are experiencing an ongoing sore throat, ask your ear, nose, and throat specialist to examine you.
1907: Samuel Simon patented the first screen printing method in Manchester, England, which was most commonly applied to wallpaper and expensive fabrics. He used rubber bands or squeegees, which are still commonly used in the screen printing process today.
Laser Printer of Gary Starkweather. In 1938 the American physicist and inventor Chester Carlson (1906-1968) (see the nearby image) invented a dry printing process, called later Xerography (the word comes from the Greek for dry writing), the foundation technology for copiers and laser printers to come.