There is more than one galaxy in the universe.

宇宙中不止一个星系。

There are billions of galaxies in the universe.

宇宙中有数十亿个星系。

Hydrogen is the lightest element in the universe.

氢气是宇宙中最轻的元素。

The hydrogen atom is the lightest element in the universe.

氢原子是宇宙中最轻的元素。

The galaxy is one of many galaxies in the universe.

银河系是宇宙中众多星系之一。

There are countless galaxies and planets in the universe.

宇宙中有无数的星系和行星。

The scientist studies macroscopic phenomena in the universe.

科学家研究宇宙中的宏观现象。

Scientists postulate that dark matter exists in the universe.

科学家假设宇宙中存在暗物质。

Astrophysics studies celestial bodies and phenomena in the universe.

天体物理学研究宇宙中的天体和现象。

The speed of light is the fastest speed in the universe.

光速是宇宙中最快的速度。