Ключевые слова: background, board, caucasian, chalk, chalkboard, child, desk, drawing, education, experience, eyeglasses, female, formula, girl, glasses, gravitation, gravity, green, happy, illustration, knowledge, learn, mass, one, phenomenon, physical, physics, picture, portrait, posing, preschool, pupil, school, schoolchild, schoolgirl, schoolkid, sketch, skill, smile, solve, student, studio, study, weight, white,