Final answer:
Light waves can undergo refraction and oscillation, but not fusion or gravity.
Step-by-step explanation:
Light waves can undergo refraction, which is the bending of light as it passes from one medium to another. This can be observed when light passes from air to water or from air to glass, for example. Light waves also undergo oscillation, which refers to the back-and-forth motion of the electric and magnetic fields that make up the light wave. However, light waves do not undergo fusion or gravity.