Precambrian

例句：

1. 1. The Precambrian era is the oldest known geological period.
   前寒武纪是已知的最古老的地质时期。
2. 2.The discovery of a new species in the Precambrian rocks has sparked excitement among scientists.
   在前寒武纪岩石中发现一种新的物种，激发了科学家的兴奋。
3. 3. The Precambrian landscape was characterized by vast deserts and sparsely populated land.
   前寒武纪景观以广阔的沙漠和稀少的人口为特征。