Draw ER Diagrams for the following narratives. 1. The Human League Surgery has doctors, nurses, midwives and patients. The patient has to telephone for appointments with the doctors or nurses and these appointments are allocated by the receptionist. An appointment can only be made with one doctor, midwife or nurse at a time. A patient may also only be registered with one doctor. 2. "Authors are responsible for writing plays that are performed in theatres. Every time a play is performed, the author will be paid a royalty (a sum of money for each performance). Plays are performed in a number of theatres; each theatre has maximum auditorium size, and many people attend each performance of a play. Many of the theatres have afternoon and evening performances. Actors are booked to perform roles in the plays; agents make these bookings and take a percentage of the fee paid to the actor as commission. The roles in the plays can be classified as leading or minor roles, speaking or non-speaking, and male or female." 3. "A database will be made to store information about patients in a hospital. On arrival, each patient's personal details (name, address, and telephone number) are recorded where possible, and they are given an admission number. They are then assigned to a particular ward (Accident and Emergency, Cardiology, Oncology, etc.). In each ward there are a number of doctors and nurses. A patient will be treated by one doctor and several nurses over the course of their stay, and each doctor and nurse may be involved with several patients at any given time."