Practice of Using Deep-hole Presplitting Blasting Technology to Drainage Methane from Extremely- thick Coal Seam with Low Permeability是什么意思_Practice of Using Deep-hole Presplitting Blasting Technology to Drainage Methane from Extremely- thick Coal Seam with Low Permeability在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句