track trimming

例句：

1. 1. The train tracks are straight across the field.
   火车轨道穿过田野。
2. 2. They followed the trail of the lost dog.
   他们沿着丢失的狗的踪迹寻找。
3. 3. The scientist used a track to map the terrain.
   科学家使用一条轨迹来测绘地形。