diff --git a/03_Day_Operators/day-3.py b/03_Day_Operators/day-3.py
index bacdf837..b1402885 100644
--- a/03_Day_Operators/day-3.py
+++ b/03_Day_Operators/day-3.py
@@ -9,7 +9,7 @@
 print('Division: ', 7 / 2)
 print('Division without the remainder: ', 7 // 2)   # gives without the floating number or without the remaining
 print('Modulus: ', 3 % 2)                           # Gives the remainder
-print ('Division without the remainder: ',7 // 3)
+print ('Division without the remainder: ', 7 // 3)
 print('Exponential: ', 3 ** 2)                     # it means 3 * 3
 
 # Floating numbers
@@ -17,8 +17,8 @@
 print('Floating Number, gravity', 9.81)
 
 # Complex numbers
-print('Complex number: ', 1+1j)
-print('Multiplying complex number: ',(1+1j) * (1-1j))
+print('Complex number: ', 1 + 1j)
+print('Multiplying complex number: ',(1 + 1j) * (1-1j))
 
 # Declaring the variable at the top first
 
@@ -109,7 +109,7 @@
 print('B in Asabeneh', 'B' in 'Asabeneh') # False -there is no uppercase B
 print('coding' in 'coding for all') # True - because coding for all has the word coding
 print('a in an:', 'a' in 'an')      # True
-print('4 is 2 ** 2:', 4 is 2 **2)   # True
+print('4 is 2 ** 2:', 4 is 2 ** 2)   # True
 
 print(3 > 2 and 4 > 3) # True - because both statements are true
 print(3 > 2 and 4 < 3) # False - because the second statement is false
diff --git a/04_Day_Strings/04_strings.md b/04_Day_Strings/04_strings.md
index 4377d5eb..699e7ca6 100644
--- a/04_Day_Strings/04_strings.md
+++ b/04_Day_Strings/04_strings.md
@@ -600,3 +600,5 @@ The area of a circle with radius 10 is 314 meters square.
 🎉 CONGRATULATIONS ! 🎉
 
 [<< Day 3](../03_Day_Operators/03_operators.md) | [Day 5 >>](../05_Day_Lists/05_lists.md)
+
+
diff --git a/11_Day_Functions/11_functions.md b/11_Day_Functions/11_functions.md
index f7bd8f9a..021c92a8 100644
--- a/11_Day_Functions/11_functions.md
+++ b/11_Day_Functions/11_functions.md
@@ -373,6 +373,9 @@ print(do_something(square_number, 3)) # 27
 
 🌕 You achieved quite a lot so far.  Keep going! You have just completed day 11 challenges and you are 11 steps a head in to your way to greatness. Now do some exercises for your brain and muscles.
 
+## Testimony
+Now it is time to express your thoughts about the Author and 30DaysOfJavaScript. You can leave your testimonial on this [link](https://testimonify.herokuapp.com/)
+
 ## 💻 Exercises: Day 11
 
 ### Exercises: Level 1
diff --git a/30_Day_Conclusions/30_conclusions.md b/30_Day_Conclusions/30_conclusions.md
index 5f8f2cf2..555869b6 100644
--- a/30_Day_Conclusions/30_conclusions.md
+++ b/30_Day_Conclusions/30_conclusions.md
@@ -24,10 +24,14 @@
 
 # Day 30
 
+
 ## Conclusions
 
 In the process of preparing this material I  have learned quite a lot and you have inspired me to do more. Congratulations for making it to this level. If you have done all the exercise and the projects, now you are capable to go to  a data analysis, data science, machine learning or web development paths. [Support the author for more educational materials](https://www.paypal.com/paypalme/asabeneh).
 
+## Testimony
+Now it is time to express your thoughts about the Author and 30DaysOfJavaScript. You can leave your testimonial on this [link](https://testimonify.herokuapp.com/)
+
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