Ключевые слова: 3034 years, 5559 years, adults only, boiler suit, bulgarian ethnicity, caucasian appearance, color image, concentration, confidence, discovery, examining, expertise, focus, high angle view, holding, hygiene, italian ethnicity, laboratory flask, liquid, mature man, mid adult man, protection, protective goggles, safety, science, scientific experiment, scientist, scrutiny, selective focus, skill, southeastern european descent, southern european descent, standing, studio shot, two people,