A study commissioned by Norcal found that 70% of the material going into the pit could have been recycled.
一份由诺克尔委托进行的调查表明，在将要进入堆填的废品中，有百分之七十的部分本是可回收的。
2
It is showed that:(1)the major surface damage patterns due to grinding are microplastic deformation trace, fracture chipping pit, microcracks, and subsidence in the loosen region of material;
结果表明：磨削损伤的主要形式有显微塑性变形磨痕、断裂剥落坑、磨削微裂纹和材料疏松区的塌坑；
3
The paper first determined the range of Zhongjiashan goaf based on using material-probe method and pit base investigation.