在基础光学实验中，我们先测量薄透镜的焦距，再判断它是会聚透镜还是发散透镜。
In a basic optics experiment, we first measure the focal length of the thin lens and then determine whether it is a converging or diverging lens.
In a basic optics experiment, we first measure the focal length of the thin lens and then determine whether it is a converging or diverging lens.