Keywords
20-25, 20-25 years, 30-35, 30-35 years, 35-40, 35-40 years, adult, adults, adults only, away, blackboard, button, button down shirt, caucasian, caucasian ethnicity, chalk, challenge, classroom, cloth, clothing, coat, college, college student, down, education, ethnicity, explaining, eyeglasses, formal, formal clothing, four, four people, front, front view, gray, gray hair, hair, head, head and shoulders, hold, holding, human, human head, indoors, instruction, look, looking, looking away, mathematics, men, mid, mid adult, mid adult men, notebook, occupation, pants, pen, people, point, pointing, professor, purestock, rear, rear view, shirt, shoulders, stand, standing, student, studying, teach, teaching, tilt, university, view, waist-up, women, write, writing, years, young, young adult, young women, 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, 1574r-014946b, 1574r 014946b, 1574r014946b