How to test the sound

How to test sound: author: Cindy Daltonalanguage: Arabicpublication date: 2004book format: paperbackpublisher: Dar Al-Arabia for Science Publishersnumber of pages: 30book category: childrendescription: What is light made of? Why do your ears hurt when someone scratches the blackboard? Why do you always fall downward and not upward? This series takes you on a journey starting from inside a very tiny atom to the dimensions of outer space. Test the scientific experiments in the books to see for yourself how gravity, sound, simple machines, and others work. If you are studying natural sciences in school, these books are a great way to deepen or advance!