Ключевые слова: abstract, art, astronomy, background, basketball, biology, blurred, board, book, brain, brush, chemistry, collection, college, design, diploma, education, english, globe, graduation, icon, illustration, knowledge, laboratory, learning, library, line, linear, maths, microscope, outline, pen, pictogram, read, ruler, school, science, set, sign, sport, student, study, symbol, test, thin, trophy, university,