track condition

例句：

1. 1. The detective was able to trackdown the thief using his surveillance footage.
   侦探利用监控录像找到了小偷。
2. 2. The teamfollowed the trail of breadcrumbs leftby the lost dog.
   团队沿着丢失狗留下的面包屑的踪迹寻找。
3. 3. The scientistswere able to track the virus'sspread through the city.
   科学家们能够通过城市中病毒的传播轨迹来追踪它。