21. (5 points) Make like a computer and trace through the following Cr+ code. Show the output of the following program void foo (int x) ( cout x int max(int a, int b)f If (a > b) return a else return b; int min(int a, int b) If (a > b) return b; else return a; int main) t foolmin (max(2,4), 5), 1): Answer 22. (5 points) what is the difference between a counter-controlled loop and a sentinel- controlled loop? 23. (5 points) How many actual parameters does the following function protoype have? int foobar(int a, int b, int c)