focal distance

例句：

1. 1.The camera is set at a focal distance of 20 cm.
   相机的焦距设置为20厘米。
2. 2. The scientist used the telescope to measure the focal distance of the star.
   科学家用望远镜测量了那颗星的焦距。
3. 3.The lens was adjusted to focus on the distant mountain, achieving a focal distance of 5 meters.
   镜头被调整到聚焦远处的山峦，达到了5米的距离。