Have you ever heard of echo? Echo is an acoustic phenomenon that occurs when a sound wave hits an obstacle and is reflected back to us, causing us to hear the sound a little later than normal and repeatedly.
Thanks for visiting us! If you want your children to smile and learn, subscribe! :D
If you like our videos, download Smile and Learn now. You’ll discover thousands of activities for children aged 3 to 12 years, all designed by educators. We have hundreds of games, interactive stories and videos in five languages: English, Spanish, Portuguese, Italian, Turkish and French. Try a month for free and start the adventure!
www.smileandlearn.com
![](https://s2.save4k.ru/pic/UtrWTBRSLvA/maxresdefault.jpg)