Deleted 01.curriculum/01.physics-chemistry-biology/01.niv1/06.nature-of-light/01.light-intensity/06.course-level-down/page.en.md, 01.curriculum/01.physics-chemistry-biology/01.niv1/06.nature-of-light/01.light-intensity/06.course-level-down/page.es.md, 01.curriculum/01.physics-chemistry-biology/01.niv1/06.nature-of-light/01.light-intensity/06.course-level-down/page.fr.md files