time-setting ring

例句：

1. 1. The time-setting ring on the watch is very precise.
   手表上的计时环非常精确。
2. 2. He used a time-setting ring to measure the distance between two points.
   他使用一个计时环来测量两点之间的距离。
3. 3. The time-setting ring on the car dashboard is essential for navigating the city.
   汽车仪表盘上的计时环对于在城市中导航至关重要。