Keywords
60-64 years, above 30, authority, bavaria, blackboard, caucasian appearance, chalk, chemistry, chemistry class, classroom, color, complexity, confidence, education, education occupation, expertise, formula, germany, handwriting, high school, human arm, human hand, ideas, indoors, lab coat, learning, manching, one person, part of, photography, rear view, science, selective focus, senior men, series, teacher, teaching, vertical, western script, working, writing, stock image, images, royalty free photo, stock photos, stock photograph, stock photographs, picture, pictures, graphic, graphics, fine art prints, print, poster, posters, mural, wall murals, 943037