1. What are three characteristics that every recursive method must have? 2. What is the base case in the method countdown? What is the recursive call? 3. Why can a recursive method cause a stack...

1. What are three characteristics that every recursive method must have?

2. What is the base case in the method countdown? What is the recursive call?

3. Why can a recursive method cause a stack overflow?

4. Revise the methods defined to use the same indices for parameters as are used by the methods Arrays.sort and Arrays.binarySearch in the Java Class Library.