My favorite food is pizza, its one of the most popular foods int he world. 
I like pizza, too! Where in the world is it most popular?
in europe and in North America I believe. 
Where exactly in Europe?
I am not sure but I do know that modern pizza was invented in Naples. 
What exactly does "modern pizza" mean? What was old pizza like?
Neapolitn pizza is more of a traditional specialty.