traces

The phone company was unable to trace the call.

电话公司查不出这个电话来自何处。

Did you draw this picture yourself, or did you trace it?

这幅画是你自己画的，还是你描摹的？

The phone company put a trace on the call.

电话公司用电子仪器追踪了这次通话。

Traces of drugs were found in his blood.

在他的血液中发现了少许毒品。