猎人追踪着动物的足迹穿过森林。

The hunter ___traced the animal's footprints through the forest.

科学家正在追踪病毒的来源。

Scientists are trying to ___trace the origin of the virus.

她用描图纸描摹了花朵的轮廓。

She ___traced the flower's outline using tracing paper.

警方正在追踪这起盗窃案的线索。

The police are trying to ___trace the clues of the theft case.