Cotton cloth, metal minerals and machinery are all industrial products. As can be seen from the table, the import value of cotton cloth and metal minerals has decreased, while the import value of machinery has increased. Thus, B is wrong. Because the import volume of the three commodities has increased and decreased, it cannot reflect the expansion of commodity exports from big countries to China. You should choose C. Machinery is an important equipment in industrial and mining enterprises. This increase in import value reflects the expansion of equipment demand and the development of industrial and mining enterprises in China.