CONSTRUCTION, REPAIR, MAINTENANCE AND SUPERVISION OF BUILDING, ENGINEERING, AND OTHER PROJECTS, INCLUDING POWER PLANTS, WATER RESERVOIRS, AQUEDUCTS, BRIDGES, SUBWAYS, RAILWAYS, AIRPORTS, INDUSTRIAL AND MUNICIPAL BUILDINGS; CONSTRUCTION, MAINTENANCE AND SUPERVISION OF ELECTRICAL POWER AND COMMUNICATION SYSTEMS, MACHINES, DEVICES, APPLIANCES, INCLUDING REPAIR OF RADIO AND TELEVISION, MAINTENANCE AND REPAIR OF INTRAOFFICE TELEPHONE AND OTHER COMMUNICATION INSTALLATIONS AND EQUIPMENT, MEASURING AND FAULT-LOCATING SERVICES; SERVICE AND REPAIR OF ELECTRON MICROSCOPES AND X-RAY DIFFRACTION EQUIPMENT; SERVICE AND REPAIR OF X-RAY AND OTHER MEDICAL AND DENTAL EQUIPMENT

PROCESSING AND TREATMENT OF MATERIALS AND PRODUCTS IN THE FIELDS OF ELECTRICAL ENGINEERING, ELECTRONICS, CHEMICAL ENGINEERING AND STRUCTURAL AND CIVIL ENGINEERING-NAMELY, MECHANICAL PROCESSING AND FORMING SUCH AS PRESSING, SINTERING AND METAL-WORKING METHODS EMPLOYED IN METALLURGY, ELECTROLYTIC PROCESSES, CURRENT-LESS CHEMICAL PROCESSES, HIGH-SPEED FORMING, MAGNETIC FORMING FOR OTHERS