Ключевые слова: 20s, 30s, 40s, 50s, adult education, background, black, caucasian, chair, classroom, college, concentrate, concentration, desk, education, female, hispanic, holding, indoors, learn, learning, lecture, lecture hall, looking at camera, looking away, male, man, mature adult, mature students, mid adult, notebook, notepad, notes, paper, pen, sitting, smile, smiling, student, students, study, studying, table, taking notes, university, window, woman, work, working, writing, young adult,