Develop an enhanced entity-relationship diagram based on the following project description:

As a large service organization, Mountain View Community Hospital depends on a large number of persons for its continued success. There are four groups of persons on whom the hospital is most dependent: employees, physicians, patients, and volunteers. Of course, some common attributes are shared by all of these persons: Person_ID (identifier), Name, Street_Address, City, State, Zip, Birth_Date, and Phone.

Each of the four groups of persons has at least one unique attribute of its own. Employees have a Date_Hired, Volunteers have a Skill, Physicians have a Specialty and a Pager#, and Patients have a Contact_date (date of first contact with the hospital). Some other persons in the hospital community do not belong to one of these four groups (their numbers are relatively small). However, a particular person may belong to two (or more) of these groups at a given time (e.g., Patient and Volunteer).

Employees are subdivided into three groups: nurses, staff, and technicians. Only nurse has the attribute Certificate, which indicates the qualification (RN, LPN, etc.). Only staff has the attribute Job_Class, and only technician has the attribute Skill. Each nurse is assigned to one (and only one) care center. Attributes of care center are Name (identifier) and Location. A care center may have one or more nurses assigned to it. Also, for each care center, one of the nurses assigned to that care center is appointed nurse_in_charge.

Each technician is assigned to one or more laboratories. Attributes of laboratory include Name (identifier) and Location. A laboratory must have at least one technician assigned to it and may have any number of technicians assigned.

There may be no beds assigned to a care center, or a care center may have one or more beds (up to any number) assigned to it. The attributes of bed are Bed_ID (identifier) and MaintenanceTime. Bed_ID is a composite attribute, with components Bed# and Room#.

Draw an ER diagram based on the business rules described in the scenario.

Please draw on paper or lucid so it can be easy to understand