Identity whether each of the following sets is well-defined or NOT Put a check mark ( if it is well-defined and a cross mark (x) if it is not. Write your answer in the space provided before the number 1. The set of all even numbers from 2 to 10. 2. The set of all factors of 18. 3. The set of responsible citizens. 4. The set of letters in the word "FATHER" 5. The set of hardworking front liners.