短語(yǔ)詞組短語(yǔ)open -pit mining machines 露天采礦機(jī)open pit -underground combined mining 露天地下聯(lián)合開(kāi)采Open -pit mining technology 露采工藝coal open -pit mining 露天采煤Deep open -pit mining 深凹露天 返回 open pit mining