A(n)is a reflected
sound wave.

A reflected sound wave can be one of two things, an echo or a reverberation. Reverberation happens when sound bounces off surfaces and reaches back to the ear within 0.1 seconds. Echoes happen when sound waves bounce back to the ear after more than 0.1 seconds.

Explanation:

hehe

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.