Oil drilling and production special equipment manufacturing; oil drilling and production special equipment sales; deep-sea oil drilling equipment manufacturing; deep-sea oil drilling equipment sales; mechanical equipment research and development; mechanical equipment leasing; special equipment repair; biomass liquid fuel production equipment sales; gas and liquid separation and purification equipment sales; environmental protection special equipment sales; special equipment sales; hydraulic power machinery and components sales; mechanical parts and components processing; general mechanical equipment installation services; gas compression machinery sales; pneumatic power machinery and components sales; mechanical and electrical equipment sales; automobile sales; automotive parts retail; motor vehicle repair and maintenance; mechanical equipment sales; housing leasing; non-residential real estate leasing; property management; information consulting services (excluding licensed information consulting services); leasing services (excluding licensed leasing services); import and export of goods; technical services, technology development, technology consulting, technology exchange, technology transfer, technology promotion; road freight transport for general cargo vehicles with a total mass of 4.5 tons or less (excluding online freight and dangerous goods).