八十年代初，北京建井研究所在实验室进行了缝管锚杆探索实验取得了良好效果。

The early eighties, the Beijing Research Institute to build wells conducted in the laboratory experiments to explore seam pipe bolt achieved good results.

youdao

八十年代初，北京建井钻研所在实验室进行了缝管锚杆探索实验取得了良好效果。

The early eighties the Beijing Research Institute to build Wells conducted in the laboratory experiments to explore seam pipe bolt achieved good results.

youdao

八十年代初，北京建井钻研所在实验室进行了缝管锚杆探索实验取得了良好效果。

The early eighties the Beijing Research Institute to build Wells conducted in the laboratory experiments to explore seam pipe bolt achieved good results.

youdao