elliptical extragalactic nebula

例句：

1. 1.The elliptical orbit of the planet is fascinating to watch.
   行星的椭圆轨道令人着迷。
2. 2.The elliptical galaxy is a popular subject in astronomy.
   椭圆星系是天文学中一个受欢迎的主题。
3. 3.The elliptical shape of the moon makes it difficult to see from Earth.
   月球的椭圆形状使得从地球看很难看到。