Uranus is an ice giant with a small rocky core and a thick mantle of ammonia, water, and methane.

天王星是一颗冰巨星，有一个小岩石内核一层由、甲烷成地幔。

It was probably composed of methane, ammonia, water, and hydrogen—no free oxygen was present.

它可能由甲烷、、氢成——不存在游离氧。

Today you learned that Uranus and Neptune are ice giants, with small rocky cores, thick mantles of ammonia, water, and methane, and atmospheres that make them look greenish and blue.

今天你学到了天王星海王星是冰巨星，有小岩石内核，有由、甲烷成地幔，以及使它们看起来呈绿色蓝色大气层。