What is the sound?

Jana and Hana hurried through the noisy roads to school.. Jana was curious to know how we hear sounds.. at school, their teacher takes them on a sound tour.. with the help of a drum beat, some books, and a pebble, the two girls quickly discover more. this book is an ideal model for home or the classroom; it contains notes for parents and teachers, with suggestions for ways to explore and interpret scientific topics. Size: 20.5*18.5 cm Number of pages: 32 pages