Sales of special equipment, key systems and components for rail transit; Sales of railway special measuring or testing instruments; Sales of electronic measuring instruments; Railway transport equipment sales; Machinery and equipment sales; Import and export of goods; Sales of industrial control computers and systems; Information technology consulting services; Machinery and equipment leasing; Technology import and export; Metrological technical services; Sales of integrated circuit chips and products (except for items subject to approval according to law, independently carry out business activities according to law with business licenses)