Question

lesson 27 - properties of waves
as light travels through the atmosphere from the sun, what can slow it down?
entering a new medium such as glass or water
light never slows down
reflecting or bouncing off an object

Explanation:

Light travels at different speeds in different media. It slows down when entering a denser medium (e.g., glass or water) from a less dense one (e.g., air). The other options are incorrect: light does slow down in media, and reflection does not change its speed.

Answer:

entering a new medium such as glass or water