Please help, thank you

[20 Points] develop a database (DB) application to manage information about employees E, the department Din which he/she works, his immediate supervisor S, and the subordinates of S (employees working under S). The information on the employees should include EName, SIN, EID, DoB (data of birth), and his department ID (DID). Also express information about the departments (location, manager), and supervisors and subordinate relationships. (1) Represent this information in an E/R diagram. (2) Convert the diagram into a relational data model. (3) For each entity set or relationship set, identify the key attribute(s), and alternate keys, if there exist. State any reasonable assumptions made to justify your design.