Consider a system that keeps track of people using their names, social security numbers, birthdays, addresses, and phone numbers. Some of these people are workers, who also have an employer and salary. The workers are one of three types: Teachers, who have a grade level that they teach and a subject that they teaching Nurses, who have a specialty and certifications Programmers, who have a set of languages that they know Draw an entity/relationship diagram that describes this system using generalization and specialization