A.煤深成變質(zhì)B.煤接觸變質(zhì)C.煤動力變質(zhì)D.煤區(qū)域巖漿熱變質(zhì)
A.簡單B.中等C.復(fù)雜D.極復(fù)雜
A.礦井資源B.生產(chǎn)C.煤礦補(bǔ)充D.煤礦工程