英语语法分析

Loose collections of these ices and small rocky particles form into comets.

这些冰和小岩石粒的松散集合形成了彗星。

However, unlike Jupiter, the terrestrial planets today are nearly void of light gases and ices.

然而，如今的类地行星与木星不同，几乎没有轻气体和冰。

The substances that make up both groups of planets are divided into three groups—gases, rocks, and ices—based on their melting points.

这两组行星的构成物质根据熔点分为三类：气体、岩石和冰。