To what extent do the derivatives and hedging methods reduce risks in the commodities markets in China.To what extent do the derivatives and hedging methods reduce risks in the commodities markets in China.To what extent do the derivatives and hedging methods reduce risks in the commodities markets in China.To what extent do the derivatives and hedging methods reduce risks in the commodities markets in China.To what extent do the derivatives and hedging methods reduce risks in the commodities markets in China.To what extent do the derivatives and hedging methods reduce risks in the commodities markets in China.To what extent do the derivatives and hedging methods reduce risks in the commodities markets in China.