You could also have added the following questions, which discuss subroutines and scoping as well:
4) What happens if you move line 7 to line 12?
5) After question 4, what happens when you do the following (in order)
+ to line 12? why?
a) Remove the parentheses
b) Remove the semi-colon
c) Precede line 12 with an ampersand (&)