Resource condition factors of influencing coal mining cost are analyzed, and predicting method of cost per ton of mined coal which is determined by coal resource condition (i.是什么意思_Resource condition factors of influencing coal mining cost are analyzed, and predicting method of cost per ton of mined coal which is determined by coal resource condition (i.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句