[7] unconsolidated materials�����̽�IJ���

[8] pit subsidence����ʽ����

[9] circular steep-sided�����ζ��ߵ�

[10] craterlike feature����ɽ��״������

[11] sag subsidence���´�ʽ����

[12] pillar punching��ú��ѹ��װ�

[13] water table������ˮλ��DZˮλ

[14] competency (strength)��������ǿ�ȣ�

[15] angle of draw���߽��

[16] twists��Ťת������

[17] splinters����Ƭ����Ƭ

[18] crumbles������������

[19] load-bearing capacity����������

[20] water circulation��ˮѭ��

[21] saturate��ʹ����

[22] wooden timbers��ľ��֧��

[23] steel I-beams������

[24] roof bolting������ê��֧��

��һҳ[1][2][3]