Design and construction of water, electricity and heating projects Design and construction of interior and exterior decoration and renovation projects; Pipeline installation (excluding the use of long-distance pipelines for transporting hazardous chemicals) works and construction; Earthwork construction Sales: Metal products (excluding precious metals), hardware and electrical machinery, pipe fittings, fire-fighting equipment, ventilation equipment, lifting equipment, valves, plumbing fixtures, power tools, coatings (except those involving hazardous chemicals), packaging materials, insulation materials, building materials, labor protection supplies, electrical switches, wires and cables, office supplies, daily necessities, sanitary ware, clothing and shoes, bearings, plastics Materials and products, electronic products, handicrafts, and chemical products (excluding dangerous chemicals and Class I precursor chemicals for drug production)