不透明瓷釉面砖
opaque ceramic glazed tile
opalescence
现代煤化工
modern coal chemical industry
Modern Coal-chemical Industry
Modern Coal-based Chemical Industry
显微煤岩组成
Micor-coal rock composition
下组煤
lower group of coal seams
lower coal seams
lower coal group
low coal group
lower growp coal
细碎粘煤
fine crushing caking coke
相思树煤病菌
Meliola acaciae-confusae sawada