英语语法分析

Before it solidified, it was just regular sand.

在凝固之前，它只是普通的沙子。

We knew that it was formed from sandstone that solidified somewhere between 150 and 300 million years ago.

我们知道它是由1.5亿到3亿年前在某地固化的砂岩形成的。

In theory, you need molten iron in the core to generate one, but Mercury is so small, its core should have long since solidified.

理论上，你需要核心里的熔化铁来产生它，但是水星很小，它的核心凝固还要很久。