Construction engineering construction; construction labor subcontracting; specialized construction operations. General items: Sales of refrigeration and air conditioning equipment; sales of railway transportation equipment; manufacture of high-speed rail equipment and parts; sales of high-speed rail equipment and parts; sales of pumps and vacuum equipment; manufacture of special railway measurement or inspection instruments; manufacture of railway rolling stock parts; sales of special railway measurement or inspection instruments; railway transportation auxiliary activities; sales of railway rolling stock; sales of railway transportation infrastructure equipment; sales of railway rolling stock parts; sales of rail transit engineering machinery and components; sales of advanced power electronic devices; research and development of nuclear power equipment complete sets and engineering technology; manufacture of technical glass products; manufacture of environmental emergency technical equipment; information technology consulting services; technical, information, and facility construction and operation services related to agricultural production; integrated application of satellite technology systems; manufacture of environmental protection special equipment; manufacture of environmental emergency detection instruments; sales of marine environmental monitoring and detection equipment; sales of environmental emergency technical equipment; environmental protection consulting services; soil environmental pollution prevention and control services.