Ключевые слова: adult, blackboard, business, casual clothing, caucasian ethnicity, characters, cheerful, classroom, color image, confidence, creativity, drawing art product, education, expertise, eyeglasses, eyewear, formula, indoors, intelligence, learning, lifestyles, looking, males, mathematical symbol, mathematics, men, nerd, occupation, one man only, one person, people, portrait, professional occupation, professor, real people, school building, science, scientist, sketch, smiling, standing, student, studying, teacher, teaching, university, writing, young adult,