diff --git a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/04.plane-refracting-surface-parallel-1/default.en.md b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/04.plane-refracting-surface-parallel-1/default.en.md
index 38ec7b17f..6312aed5d 100644
--- a/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/04.plane-refracting-surface-parallel-1/default.en.md
+++ b/01.curriculum/01.physics-chemistry-biology/02.Niv2/04.optics/04.use-of-basic-optical-elements/01.plane-refracting-surface/04.plane-refracting-surface-parallel-1/default.en.md
@@ -1,5 +1,7 @@
 ---
 title: 'Spherical mirror (parallel 1)'
+published: false
+visible: false
 content:
     items: '- ''@self.children'''
     order: