Ключевые слова: apartment, architecture, arrangement, array, bill, box, building, business, communication, condominium, confidentiality, contact, delivery, door, drawer, drop, envelope, individual, interior, key, letter, letterbox, line, lock, locker, mail, mailbox, many, message, metal, notice, number, office, pattern, post, postbox, privacy, room, row, school, security, sign, stack, texture, wood, wooden,