trace

The lab results showed a trace of lead in the city's drinking water supply.

(Chinese) 实验室结果显示该市的饮用水供应中含有微量的铅。

The fugitive disappeared without a trace, leaving the investigators with no clues.

(Chinese) 逃犯消失得无影无踪，给调查人员没留下任何线索。

Historians managed to trace the ancient manuscript back to a monastery in tenth-century Tibet.

(Chinese) 历史学家成功地将这份古代手稿追溯到十世纪西藏的一座修道院。

The cybersecurity team tried to trace the source of the hacking attack to a server in Europe.

(Chinese) 网络安全团队试图将黑客攻击的源头追踪到位于欧洲的一台服务器。