extragalactic systems的用法和樣例：
例句
- Earth was a beautiful place, located on the fringes of one of the galactic systems and easily reached from other galaxies.
地球是一個(gè)美麗的地方，位于銀河系的一條旋臂上，從其它星系容易到達。 - The original plan was for Earth to be an exchange center of information for all the different galactic systems.
最初的計劃就為了使地球成為一個(gè)所有不同銀河系的系統的信息交流中心。
