secondary ridge

例句：

1. 1. The mountain range is made up of several secondary ridges and valleys.
   这座山脉由几个次要的山脊和山谷组成。
2. 2.The secondary ridges are visible from the airstrip.
   从飞机跑道上可以看见这些次要的山脊。
3. 3. The geological survey revealed that the secondary ridges were formed by tectonic activity.
   地质调查发现，这些次要的山脊是由构造活动形成的。