alluviation造句

• Dig jade is it leave riverbed in river valley terrace , do beach to refer to , ancient river and alluviation , diluvian gravel that fan have dig seeking and d jade gravel of the layer in front of the mountains the jade of these places is brought by the flowing water too
  挖玉是指离开河床在河谷阶地干滩古河道和山前冲积洪积扇上的砾石层中挖寻和阗玉砾。这些地方的玉也是由流水带来的。