| 单词 | trace a river upstream back to its source |
| 释义 | trace a river upstream back to its source—溯源See also:trace something to its source [idiom.]—究其根源 trace back to the source—追根溯源 trace sth. back to its source—追根 |
| 随便看 |
英汉双解词典包含2273206条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。