相关专家坚信尽管他们在矿下有通风设备和水源，当矿井塌陷时，大量的水流入井底，也正是矿工被困的地方。
Experts insisted they had ventilation and water of a sort-when a mine caves in, water flows to the bottom, where the workers were believed to be trapped.
本文介绍了日本研制的一种隧道挖掘机。该设备可在施工中防止地基塌陷，以保证施工的安全。
This paper shows us a newly developed tunnel excavator by Japan, which can prevent ground collapse and thus assure safety in construction.
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