Jaka jest różnica między dźwięk i odgłos ?Możesz podać przykładowe zdania.

They are very close synonyms. My feeling is that "odgłos" should have a known source, so it is a sound, which is caused by something external, we usually know, or made as a response to something.
So, imagine you are in a room and hear sounds of a dog from behind the wall. "Dźwięk psa" would be probably barking, while "odgłos psa" would be the noise which it makes during moving or eating etc.
For example "odgłosy kroków" would be better than "dźwięki kroków", but "dźwięk maszyny" would be better than "odgłosy maszyny", because there is no external action which would cause the sound (if you hit a machine with a hammer, then rather the "odgłos" is made).
However, you may use them interchangeably.