extragalactic systems

• 外银河系

extragalactic systems的用法和样例：

例句

1. Earth was a beautiful place, located on the fringes of one of the galactic systems and easily reached from other galaxies.
   地球是一个美丽的地方，位于银河系的一条旋臂上，从其它星系容易到达。
2. The original plan was for Earth to be an exchange center of information for all the different galactic systems.
   最初的计划就为了使地球成为一个所有不同银河系的系统的信息交流中心。