Yixian Formation

例句：

1. 1. The Yixian Formation isa famous geological formation in China.
   中国著名的地质构造是亦仙岩组。
2. 2.The Yixian Formation contains manyunique fossils that are important for studyingthe history of life on Earth.
   亦仙岩组中包含了许多独特的化石，对于研究地球生命的历史具有重要意义。
3. 3. The Yixian Formation was discovered by archaeologists who were searching for evidence ofancient human civilizations.
   考古学家在寻找古代文明的证据时发现了亦仙岩组。