Ключевые слова: abstract, background, blackboard, blur, blurred, blurry, bokeh, boy, child, class, classroom, college, concept, defocus, display, diversity, education, exam, friends, grade, group, homework, interior, kid, knowledge, learn, learning, lecture, lesson, many, meeting, people, pupil, room, school, schoolboy, schoolchild, schoolteacher, seminar, student, study, studying, teacher, team, together, training, uniform, white, young, youth,