Ключевые слова: angle, assistance, blackboard, bulb, business, chalkboard, coach, concept, conceptual, course, development, diagram, education, educational, elearning, email, experience, expert, graph, green, hand, high, holding, improve, improvement, instructor, job, leadership, learn, lesson, light, management, motivation, overhead, pen, people, person, personal, practice, professional, star, study, teaching, text, top, trainer, training, view, web, writing,