diff --git a/content/chapters/data/lab/content/arena.md b/content/chapters/data/lab/content/arena.md
index 96cadd7fa3..d46b2f84bf 100644
--- a/content/chapters/data/lab/content/arena.md
+++ b/content/chapters/data/lab/content/arena.md
@@ -88,33 +88,3 @@ Notice how the array's memory  is automatically managed.
    After completing the exercise, make sure that the memory is properly managed.
 
 1. Play with your reference counted array and create different scenarios to test its limits.
-
-## Use-After-Free
-
-TODO
-
-## Code Injection
-
-TODO
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-### Quiz
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-TODO
-
-## DEP
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-### Practice
-
-TODO
-
-## Code Reuse
-
-TODO
-
-### Quiz
-
-TODO
-
-### Practice
-
-TODO