. Each semester, students register for courses offered by various departments and schools within the university. Not all persons register on the same day. Therefore, students are assigned specific registration dates and times. These details are communicated to registrants through mail. The permit, which is sent to the permanent address of the individual well in advance, contains the date and time of registration, as well as personal identification data (name, student number, academic standing, and matriculation status). Individuals must prove they have permission to register when they appear on a specific date and time at the registration hall. The permit itself need not be shown. They receive approval, and a record is made that they did appear at the appointed time. (This prevents others from appearing to impersonate an earlier registrant.) In some cases students telephone in advance to learn of their assigned dates and times. Permits do not reach everyone, for various reasons. During actual registration, students are allowed to sign up for any courses that are still accepting registration (i.e., that are not full and therefore closed) and for which they have met the prerequisites. (Students are responsible for ensuring they know about and have met the prerequisites.-) When they register, their name, student identification number, and course credits are added to their registration record. The last phase of registration is the payment of fees. Students pay tuition based on whether they are financial aid recipients or not , the numbers of credits they register for, and their academic standing (deans list 25% and presidents list 30% discount). Tuition per credit varies by college within the university. Depending on whether students are in full- or part-time status (determined by the number of credits being carried), they may be assigned an internet fee (for part timers only). - Give the entity classes involved in the above case and mention the attributes in each of the entity classes you identified and underline the fields that are the keys.