as DNA in illegally traded rhino horn can be tracked back to its origin.因为根据被非法交易的犀牛角中的DNA，可以追踪到其来源

track back 后退，跟踪

The earliest currency of China can track back to millenary years ago.

中国最早的货币可以追溯到几千年前。

相关短语take the back track回去; 退去

Two days we lingered,then took the back track.

我们逗留了两天，就回来了。

This female has reacted badly to the anaesthetic.那头雌犀牛对麻醉剂产生了严重不良反应

react to对 ... 起反应

How do you react to this modern artist's paintings?

你对这位现代艺术家的画有何评价？

How did they react to your suggestion?

他们对你的建议有什么反应？