Ключевые слова: academic, adult, aged, background, blackboard, board, business, career, caucasian, chalk, chalkboard, classroom, college, confident, copy, education, educator, exam, explaining, facilitator, green, happy, institute, instructor, job, learn, lecturer, lesson, male, man, mature, mentor, middle, person, portrait, professional, school, science, senior, smart, smiling, space, student, teacher, text, trainer, tutor, university, work, writing,