| 例句 |
The electrons moved in planetary orbits.电子在绕原子核轨道上运动。We now know a lot more about the early stages of planetary formation.我们现在对行星形成过程的早期阶段有了更多的了解。Within our own galaxy there are probably tens of thousands of planetary systems.在我们所处的银河系中，大概有数万个行星系。 |