boundary edge

例句：

1. 1. The boundary between the two countries isclearly marked.
   两国之间的边界非常明显。
2. 2. The car's edge was scratched by astone.
   汽车的边缘被一块石头划伤了。
3. 3.The artist used a brush to create theboundary edge of the painting.
   艺术家用刷子创作了这幅画的边界边缘。