Ключевые слова: air, allergy, asthma, background, clean, cleaner, closeup, detail, diagonal, dust, empty, fiber, filter, filtration, foreground, fullframe, grid, hepa, highefficiency particulate air, home, housekeeping, level, line, linear, material, new, paper, part, physical, pollution, protection, repair, selective focus, service, shallow depth of field, smog, system, technology, ventilation, white,