Update annex.en.md

01.curriculum/01.physics-chemistry-biology/03.niv3/02.geometrical-optics/05.paraxial-optics/02.paraxial-optics-simple-elements/03.lens/03.lens-beyond/annex.en.md

@@ -15,7 +15,10 @@ media_order: 'lentille-boule-orleans-1bis.jpg,lensball-brut-820-760.jpg,Einstein
 !<summary>
 ! I choose it
 ! </summary>
-! A lensball is a polished spherical ball of radius $`R=5 cm`$, made of glass of refractive index value $`n_{glass}=1.5`$. The cathedral is 90 meters high, and you stand with the lensball 400 meters from the cathedral. You look at the cathedral through the lens, your eye being at 20 cm from the center of the lens. What would you expect to see? 
+! A lensball is a polished spherical ball of radius $`R=5 cm`$, made of glass of refractive 
+index value $`n_{glass}=1.5`$. The cathedral is 90 meters high, and you stand with the lensball 
+400 meters from the cathedral. You look at the cathedral through the lens, your eye being at 20 cm 
+from the center of the lens. What would you expect to see? 
 !
 ! * _The resolution time is the typical expected time to be allocated to this problem if it was part of an examen for an optics certificate_. 
 !