短语词组短語lean -coal 雙強煤粉少油點火器Lean clean coal 瘦精煤rich -lean pulverized coal burner 濃淡型煤粉燃燒器lean coal burner 貧煤型燃燒器lean coal -fired 貧煤lean coal char 貧煤焦firing lean coal 燃燒貧煤production meager lean coal 貧瘦煤 返回 lean coal