Ключевые слова: book, boy, calculation, caucasian, child, childhood, count, desk, diligent, doing, education, effort, evening, exercise, focus, hard, home, homework, indoor, kid, lamp, learn, learning, lesson, light, little, male, mathematics, maths, night, person, physics, pupil, school, schoolboy, serious, sitting, solution, study, studying, table, teenage, thinking, writing, young, yours,