first caving 中文意思是什麼
first caving
解釋
直接頂初次垮落-
Discussion on recovery working face first caving technique
回採工作面初次放頂技術探討 -
First roof caving
直接頂初次垮落 -
Practice of first roof caving technology at comprehensive mechanical mining face in steep thick coal seam
急傾斜特厚煤層綜放工作面超段高初次放頂的實踐
分享友人