The following options are caused by wave reflections:
- fish appearing shallower than they are (This effect is due to the refraction of light, but it is related to wave behavior.)
- an echo in an empty hall (This is a direct result of sound wave reflections.)
- an image in a mirror (This occurs due to the reflection of light waves.)
Seeing someone through a glass window typically involves refraction and transmission rather than reflection.
So the correct selections are:
- fish appearing shallower than they are
- an echo in an empty hall
- an image in a mirror