超前孔直径
基于1个网页-相关网页
·2,447,543篇论文数据，部分数据来源于NoteExpress
The drill would use that hole as a pilot and widen the diameter to about 28 inches, which officials have said is wide enough for the miners to be hoisted through.
CNN: Drilling to reach Chile miners yet to begin
应用推荐
模块上移
模块下移
不移动