Ключевые слова: arrow, atom, black, blackboard, board, calculation, caucasian, chalk, chalkboard, chemical, chemistry, class, clean, close, college, concept, draw, drawing, education, graph, graphic, green, hand, handwriting, holding, horizontal, illustration, line, liquid, mature, molecule, numbers, one, person, school, science, scientific, student, style, stylish, teach, teacher, text, university, up, white, work, write, writing, young,