他在沙滩上留下了轨迹。

He left a trace on the beach.

这条小路的轨迹很难辨认。

The trace of this path is hard to recognize.

他们在地图上标出了旅行的轨迹。

They marked the trace of their journey on the map.

科学家们试图找到病毒的轨迹。

Scientists are trying to find the trace of the virus.

他的脚印在雪地里留下了清晰的轨迹。

His footprints left a clear trace in the snow.