planetary milling machine

例句：

1. 1. The planetary nebula is a fascinating object in the night sky.
   行星状星云是夜空中一个迷人的天体。
2. 2. The discovery of dinosaurs has led to our understanding of the planetary system.
   恐龙的发现使我们对行星系统有了更深入的理解。
3. 3. The planetary scientists are studying the effects of climate change on the Earth's atmosphere.
   行星科学家们正在研究气候变化对地球大气层的影响。