Sound travels in waves.
2 Our ears and brain work together so that we can hear.
3 Sound travels through air, liquid and solid materials.
4 Cats, rabbits and horses don't hear as well as people.
mana and i were also a little more to me than a few others that would be a little bit more fun to see the new levels of this app to the time and the time you have a little time and you have a great game to watch your game play and you have a lot