大分水岭

例句：

1. 1. The mountain range forms the boundary between the two countries.
   这座山脉是两国之间的分界线。
2. 2. The river divides the town into two distinct neighborhoods.
   这条河将这个镇分成两个不同的街区。
3. 3. The ridge acts as a natural barrier separating the forest from the plain.
   这个山脊作为自然的屏障，将森林与平原分隔开来。