focal conic

例句：

1. 1.The focal conic of the lens is crucial for its functioning.
   透镜的焦点圆锥体对其功能至关重要。
2. 2. The focal conic of the lens focuses light onto the retina.
   透镜的焦点圆锥体将光线聚焦到视网膜上。
3. 3.The focal conic of the lens can be adjusted to focus on different objects.
   透镜的焦点圆锥体可以调整以聚焦于不同的物体。