Ключевые слова: adult, attractive, beautiful, blackboard, blur, boys, caucasian, chalkboard, children, class, classmates, classroom, education, gesture, girls, indoors, kids, knowledge, learn, lesson, math, mathematics, people, point with finger, preadolescent, preteen, pretty, profession, pupils, raised hand, school, schoolboys, schoolchildren, schoolgirls, schoolkids, signs, study, symbols, teacher, together, woman,