Definition
To be actively searching for someone or something by carefully examining clues or information about their whereabouts.
追蹤（某人或某物）
The police are on the trail of the suspects in the bank robbery.
警方正在追蹤銀行搶劫案的嫌疑人。
The detectives are on the trail of the murderer, following the slightest clues found at the crime scene.
偵探們正在追蹤兇手，追隨犯罪現場發現的最微小線索。
After years of research, scientists are finally on the trail of a cure for the disease.
經過多年的研究，科學家們終於找到了治療這種疾病的方法。