bielliptical

例句：

1. 1.The geometry of the hyperbola is quite complex.
   双曲线的几何形状相当复杂。
2. 2.The bisectrix divides the plane into two equal halves.
   双割线将平面分成两个相等的部分。
3. 3.In a hyperbola, the distance from one focus to the other is always greater than the distance between the foci.
   在双曲线中，从一个焦点到另一个焦点的距离总是大于焦点之间的距离。