The fitness club offers many classes, each of which has attributes (ClassID, ClassDesc, ClassSchedule). The ClassSchedule is a composite attribute consisting of (ClassDate, ClassTime). Each class is taught by one instructor who has attributes (InsID, InsName). One instructor can teach multiple classes while each class is taught by only one instructor. Some instructor may have never taught any class yet. The club also records information about its members, each of which has attributes (MemberID, MemberName, MemberAddress). A class should have at least one members attending it. Some members do not attend any class while some may attend multiple classes.