In the following exercises, create an ERD with proper maximum cardinality for each question. You must include all PKs and FKs. Label each relationship as 1:1, 1:M, or M:N; name each relationship. Include also one other attribute for every table (just include one for brevity; obviously a real table would have several other attributes).

1. Each student is assigned to one professor (for advising purposes). A professor may have zero, one, or many advisees.

2. A patient can make zero or several appointments at a HMO.

3. A student may only live in one dormitory (though dormitories are not required for students). Further, a dormitory may have no students (unused in the summer for example).

4. Students may belong to several clubs; clubs obviously have several students.

5. An author writes one or many books; books are written by one or more authors.

Extra Credit: Doctors are treated by one or more (or none if they are never sick) other doctors.