great circle of a sphere

例句：

1. 1.The great circle of the sphere isthe path that the sun takes to reachthe earth.
   球体的大圆周是太阳到达地球的路径。
2. 2. The greatcircle of the sphereis also known as the equatorial line.
   球体的大圆周也被称为赤道线。
3. 3. The great circleof the sphere is used to measurethe distance between two points on the surfaceof the earth.
   球体的大圆周用于测量地球表面两点之间的距离。