Ключевые слова: 2529 years, 3034 years, above 25, authority, beijing, care, caucasian ethnicity, china, chinese ethnicity, color image, doctor, endoscope, endoscopy, examining, expertise, glasses, healthcare and medicine, healthcare worker, holding, horizontal, hospital, indoor, low angle view, lying down, mask, medical equipment, medical instrument, medical procedure, medical record, mid adult men, mid adult women, multiethnic group, operating gown, operating room, patient, photography, preparation, professional occupation, protective workwear, skill, standing, surgeon, surgery, surgical cap, surgical mask, teamwork, three people, tilt, togetherness, unrecognizable person, waist up, working, young men,