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

天王星是颗冰巨星，有个小岩石内核由氨、水甲烷成的厚厚的地。

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

能由甲烷、氨、水氢成——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，有小的岩石内核，有由氨、水甲烷成的地，以及使们看起来呈绿色蓝色的大气。