用线程模拟地球和月亮的运行轨迹。地球沿椭园轨道绕太阳运转，太阳在椭园轨道的一个焦点上。月亮沿园形轨道绕地球旋转。-Earth and the Moon with a thread running simulation trajectory. Earth' s elliptical orbit around the sun along the sun in elliptical orbits at a focus. Park along the moon-shaped orbit around the Earth' s rotation.