Ключевые слова: 20s, academic, adult, african, american, boy, burn, caucasian, chemical, chemistry, classmate, classroom, demonstrate, desk, education, female, high, holding, indoor, intelligence, knowledge, lab, labcoat, learning, male, multiethnic, occupation, people, portrait, research, school, schoolboy, science, show, smile, stick, student, study, teacher, teen, teenage, teenager, three, university, woman, women, young,