Auniversity consists of several faculties. within each faculty there are several departments. each department may run a number of courses. all teaching staff is attached to departments, each staff member belonging to a unique department. (note: see how many meanings you can assign to this ambiguous sentence). every course is composed of sub-courses. some sub-courses are part of more than one course. staff may teach on many sub-courses and each sub-course may be taught by a number of staff. draw an entity-relationship model for this example. show both cardinalities and optionalities. put a question mark where the degree is not clear from the text. don't assume anything; rather, write a list of questions you would have to find answers to in order to complete the model.