Manufacturing, processing, sales, and repair of railway locomotive and rolling stock parts, railway special equipment and materials, and railway special equipment accessories; manufacturing, processing, and sales of auto parts, plastic products, primary plastics, and metal stampings; sales of metal materials and textile raw materials; ordinary road freight transport; design, manufacturing, and sales of aircraft and helicopter parts, marine supporting equipment parts, and non-metallic ships; self-operated and agent import and export of various commodities and technologies, except those restricted or prohibited by the state.