Mechanical parts processing; Mechanical processing; Mold manufacturing; Sales of hardware products; Communication system equipment manufacturing; Sales of communication equipment (excluding wireless radio and television transmission and satellite ground receiving equipment); Sales of electronic products; Sales of plastic products; Manufacturing of daily plastic products; Sales of metal products; Manufacturing of metal daily necessities; Manufacturing of automobile parts and accessories; Manufacturing of motorcycle parts and accessories Sales of building materials; sales of steel; sales of aluminum; sales of office supplies; manufacturing of general instruments and meters; manufacturing of special instruments and meters (excluding licensed business items); sales of instruments and instruments; maintenance of computers and office equipment; installation and maintenance of mechanical equipment (excluding special equipment); import and export of goods and technology (except for the import and export of goods and technology prohibited by the state or involving administrative approval). (The above industrial industries are limited to branches operating in industrial parks).