Ключевые слова: background, biology, board, caucasian, chalkboard, chemical, chemist, chemistry, child, class, classroom, college, concept, discovery, drawing, education, equation, experiment, formula, girl, glass, hand, knowledge, laboratory, learn, learning, lecture, lesson, little, man, molecule, person, professional, research, school, schoolgirl, science, scientific, scientist, smart, solution, structure, student, study, teach, teacher, technology, theory, university, write,