planetary orbit的用法和樣例：
例句
- The orientation of the planet's orbit is changing continuously.
該行星軌道的方向不斷變化。 - Under proposed International Astronomical Union definitions, two planets that orbit each other around a barycenter between them are a binary planet.
根據國際天文學會的定義提出兩個行星軌道周圍的重心在彼此之間是雙行星系統。
