(c) general items of: natural scientific research and test development; reprocessing; cable operation; construction of building and heating pipe parts and other construction metal products; engineering and technical development; sewage treatment and recycling; manufacture of specialized chemical products (without dangerous chemicals); manufacture of specialized instruments for environmental protection; manufacture of specialized instruments; sale of specialized equipment for environmental protection, subject to the approval of the relevant authorities; sale of specialized instruments for environmental monitoring; manufacture of instruments for ecological monitoring and testing; production of eco-monitoring and detection instruments; management of municipal facilities; construction of environmental services; manufacture of specialized equipment (without licensing professional equipment); engineering management services; production of technical services; technical advice for the manuf...