Question

what is echo and define compression and rarefection

Answer 1

The reflection of the sound is called echo

Answer 2

compression
A compression is are written in a longitudinal wave where the particles are close together

Rarefaction
A a rarefaction is a region in a longitudinal wave where particles are furthest apart

Echo
a sound or sounds caused by the reflection of sound ways from a surface back to the listener

i hope you understand