Ключевые слова: adult, black, blackboard, blank, caucasian, chalk, chalkart equipment, chalkboard, chalkboard visual aid, closeup, concepts, dirty, english, finger, hand, handwriting, handwritten, indoors, inscription, left hand, letter, man, message, peace, peaceful time, pink, quiet, removal, semierased, smear, smudged, text, unsharp, word,