sand pillar的意思|示意

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sand pillar相关短语

1、 sand-prevention pillar 防砂煤柱

2、 coal pillar for sand proof 防砂煤柱

3、 sand-proof pillar 防砂煤柱

4、 pillar against sand 防砂煤柱

5、 safety pillar against sand 防砂煤柱

6、 set safety pillar prevent sand 防砂煤柱留设

7、 anti-sand & anti-collapse coal pillar 防砂防塌煤柱