Update cheatsheet.en.md

10.temporary-m3p2/16.waves/20.n2/05.waves-introduction/10.waves-in-physics/cheatsheet.en.md

@@ -95,6 +95,7 @@ as a **mechanical wave**.
    *  *Diffraction* around an obstacle.
    *  *Reflection and transmission* at the interface between two different media.
    *  *Energy transport*, but *no matter transport* over long distances.
+   
    **are also found in more subtle phenomena** observed in nature and later described mathematically, or first predicted by physical theory before experimental confirmation.
 
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