In this case, Uranium-Lead Dating was used to establish that half of the sandstone in the samples was formed at the same time the granite in the Appalachian Mountains was formed.
在这种情况下，铀铅定年法被用来确定样本中一半的砂岩是在阿巴拉契亚山脉花岗岩形成的同时形成的。
2
However, the first chronic case took place half a century ago.
然而，第一个慢性中毒病例发生在半个世纪以前。
3
One and a half years later, I think the case is closed.