... 稀有元素rare element 稀有金属rare metal;less common metal 稀有气体rare gas ...
基于102个网页-相关网页
·2,447,543篇论文数据，部分数据来源于NoteExpress
Owing to the less common distribution of layered roof in metal mines, the research of the support of hard rock layered roof is relatively less and still at the initial stage.
由于金属矿层状顶板分布较少，故硬岩层状顶板的支护研究也相对较少且处于起步阶段。
youdao
应用推荐
模块上移
模块下移
不移动