一束阳光突破了浓密的云层。

A ___ray of sunshine broke through the dense clouds.

光线进入不同介质时会折射。

Light ___rays refract when entering a different medium.

黑暗中，她手电筒的一束光线照亮了道路。

In the darkness, a single ___ray of light from her flashlight revealed the path.