Mechanical equipment sales: Building materials sales, mechanical parts, spare parts sales, rail transit engineering machinery and electronic special equipment sales, construction engineering machine parts sales; Sales of pneumatic power machinery and components; Sales of metal products; Machinery sales; Technical service, technology development, technology consultation, technology exchange, technology transfer, technology dissemination; Food sales (pre-packaged food only); Furniture parts sales, auto parts wholesale, luggage sales, stationery retail hardware products retail; Electronic components retail; Sales of metal materials, Internet sales (except sales of commodities requiring licenses); Food Internet sales (only sales of pre-packaged food), information consultation services (excluding licensing information consultation services); Domestic trade agency, jewelry retail