英语语法分析

The first of these glacial periods is often called the huronian glaciation because it is well exposed in rocks just north of lake huron in southern canada.

第一次冰期称为「休伦冰期」，因其遗迹在加拿大南部休伦湖北方的岩石中清晰可见。

The early stages of the Huronian, from 2.4 to 2.3 billion years ago, seem to have been particularly severe, with the entire planet frozen over in the first "snowball Earth".

Huronian冰河期的早期，也就是从24亿到23亿年前，似乎特别寒冷，整个地球第一次冰冻起来。