Ключевые слова: 30s, african american, boy, casual clothing, caucasian, child, children, class, classroom, concentrating, concentration, desk, education, female, girl, group, happy, helping, horizontal, indoors, inside, learning, lesson, listening, male, people, person, pupil, school, secondary school, sitting, six people, smiling, student, study, studying, teacher, teaching, teen, teenage, teenager, thirties, together, tutor, writing, young,