Ключевые слова: blank, board, business, businessman, caucasian, class, classroom, clean, cleaner, clear, coach, conference, congress, convention, course, drawing, education, educational, erase, eraser, hand, knowledge, learn, lecture, lesson, male, man, meeting, message, office, presentation, school, seminar, session, student, study, teach, teacher, teambuilding, training, university, white board, whiteboard, wipe, wiper, workshop, write,