1.  What is a macro, and how do you use it?

2.  How can you avoid including a header more than once?

3.  Can a file other than a .h file be included with #include?

4.  What is the benefit of using #define to declare a constant?

5.  What is the benefit of using enum to declare a constant?

6.  What is the benefit of using an enum rather than a #define constant?

7.  How are portions of a program disabled in demo versions?

8.  Is it better to use a macro or a function?

9.  What is the best way to comment out a section of code that contains comments?

10.  What is the difference between #include and #include "file" ?