4. Consider a relation about people in the United States, including their name, Social Security number, street address, city, state, ZIP code, area code, and phone number (7 digits). - What FD's would you expect to hold? - What are the keys for the relation? 5. Consider a relation representing the present position of molecules in a closed container. The attributes are an ID for the molecule, the x, y and z coordinates of the molecule, and its velocity in the x, y, and z dimensions. - What FD's would you expect to hold? What are the keys? Answers for this exercise may vary because of different interpretations