Ключевые слова: arm, arm up, asian, ask, back, background, blackboard, boy, child, children, class, classroom, computer, concept, crowd, education, elementary school, exam, female, fun, girl, group, hand, indoor, kid, knowledge, learning, lesson, male, man, participant, present, presentation, question, raise, school, student, study, teacher, technology, training, up, vote, voting, wisdom, woman, young,