Tunnels in rock are all dug by the method by drilling a small hole, packing explosive and dynamiting.

在岩石层的隧道均采用钻眼、装药、爆破的方法开挖。

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Tunnels in rock are all dug by the method by drilling a small hole, packing explosive and dynamiting.

在岩石层的隧道均采用钻眼、装药、爆破的方法开挖。

youdao