books.google.fr - The eight lessons in this module introduce students to light sources, and the characteristics of light, such as its ability to travel and reflect. Students investigate translucent, transparent, and opaque materials, and explore the science of shadows. They also examine the evolution of light technology...https://books.google.fr/books/about/Light.html?hl=fr&id=4T-aXFsMhAgC&utm_source=gb-gplus-shareLight