Ключевые слова: 67, adult, alphabet, american, blackboard, book, boys, caucasian, child, childhood, children, classroom, desk, education, european, females, girls, glasses, green, group, happiness, human, indoors, learning, lifestyles, listening, people, person, preschool, pupil, school, schoolboy, schoolgirl, sitting, smiling, standing, studying, teacher, teaching, women,