If a girl is standing in front of a smooth surface from which a sound is reflected the girl may hear

Echo

Explanation:

Echo means sound being repeated back after a while when sound produced gets reflected back from a surface. The delay in hearing the repeated sound depends on the distance to the reflecting surface. Common example is echo can be heard from an empty well.

Thus, if a girl is standing in front of a smooth surface from which a sound is reflected the girl may hear an echo of her own voice.

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.