Archaean

例句：

1. 1. The Archaean rocks are still visible in the landscape today.
   今天的景观中仍然可以看到古老的岩石。
2. 2.The Archaean era is often referred to as the primitive era of life.
   古生代通常被称为生命的起源时期。
3. 3.The discovery of ancient tools from the Archaean period has shed new light on human evolution.
   从古生代时期发现的工具揭示了人类进化的新线索。