valley line

• 河谷线,谷线,河流谷底线,谷底线,最深谷底线

valley line的用法和样例：

例句

1. Rivers traverse the valley floor.
   多条河流穿越谷底。
2. From the top of the mountain there was a vertiginous drop to the valley below.
   从山顶向谷底望去令人眩晕。