crest curve

例句：

1. 1. The crestcurve of the mountain is a natural landmark.
   这座山的峰线是一个自然地标。
2. 2. The crest curve of the waveis where it reaches its highest point.
   波浪的峰线是它达到最高点的地方。
3. 3. The crest curve of the riveris marked by a series of rapidsand waterfalls.
   河流的峰线由一系列急流和瀑布标记。