The introduction, research and development, and sales of electromechanical and biological products and related technologies (excluding the sale of medicines and food, except for special provisions of national laws and regulations); the research and development and maintenance of bearings; the research and development, sales of electronic computers, software, hardware, and communication products (excluding radio transmitting equipment); wholesale and retail bearings (excluding rare metals); automobile parts Parts, motorcycle parts, Wujinjiaodian, metal materials and mineral products (except those with special provisions by the state); building decoration materials, chemical raw materials and products (excluding dangerous goods), daily necessities, clothing, textiles; self-operated and agent import and export of various commodities and technologies, except for commodities and technologies that are restricted by the state or prohibited from import and export.