orientable manifold

例句：

1. 1. The new map is orientable, so it can be used to navigate directions.
   新地图是可定向的，因此可以用来导航方向。
2. 2. In the study of topology, an orientable manifold is a smooth surface with boundary points that arenot isolated.
   在拓扑学中，一个可定向的流形是一个光滑的表面，边界点不是孤立的。
3. 3.The orientable manifold theory has been applied to various fields such as physics and mathematics.
   可定向的流形理论已经被应用到物理学和数学的各个领域。