<ul><li>Rubber - is an article of stationery that is used for rubbing out pencil markings. </li></ul><ul><li>On April 15, 1770, Joseph Priestley described a vegetable gum which had the ability to rub out pencil marks . </li></ul>
<ul><li>Corrector - w riting instrument in the form of feathers, the fluid in the container with a brush or as a "belt". It is used to correct errors of writing. </li></ul>
<ul><li>Razor blade was used, among others for debugging. But,unfortunately, been used for days of our grandparents. T oday ispretty to something else. </li></ul>
<ul><li>We was used : </li></ul><ul><li>Google, </li></ul><ul><li>Wikipedia. </li></ul>
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