Ключевые слова: 1, abstract, back, background, black, blackboard, blank, chalk, chalkboard, child, children, class, classroom, clean, closeup, college, color, copy, dark, design, draw, education, empty, exercise, kid, knowledge, learn, learning, lesson, nobody, object, pattern, pupil, school, september, space, student, study, studying, subject, surface, teacher, text, texture, time, top, university, view, write, writing,