警察在树林里寻找嫌疑人的踪迹。

Jǐngchá zài shùlín lǐ xúnzhǎo xiányírén de zōngjì.

The police are searching for traces of the suspect in the woods.

科学家通过卫星追踪候鸟的迁徙踪迹。

Kēxuéjiā tōngguò wèixīng zhuīzōng hòuniǎo de qiānxǐ zōngjì.

Scientists track the migration routes of migratory birds via satellites.