plane gear的用法和樣例：
例句
- Planetary gear systems are also used in many automatic transmissions.
行星齒輪組也同樣用于許多汽車(chē)變速器中。 - The bike chain drives a sun gear on the rear axle, which transmits power to planetary gears situated around it.
自行車(chē)的鏈條會(huì )驅動(dòng)后輪輪軸上的太陽(yáng)齒輪，將動(dòng)力傳送到四周的行星齒輪。
