cycloidal

例句：

1. 1.The cycloidal path of the planets is fascinating to observe.
   行星的圆周运动非常引人入胜。
2. 2. The scientist made a cycloidal model of the solar system.
   科学家制作了一个太阳系的圆周模型。
3. 3.The cycloidal motion of the earth's axis causes the seasons.
   地球轴的圆周运动导致四季更替。