QUESTION 1 Among the following list, what is not an entity? 1. A course in a university C The instructor of a course Course ID C A student 5 points QUESTION 2 The cardinality of the friend_of relationship set between two student entities in the student entity set should be: 1. one to one one to many many to one C many to many 5 points QUESTION 3 1. If there is a teach relationship between the instructor entity set and the course entity set and it requires every course must have an instructor, but some instructors may not teach any course. Which of the following statement is true? The participation of course in teach is total and the participation of instructor in teach is total. The participation of course in teach is partial and the participation of instructor in teach is total. The participation of course in teach is total and the participation of instructor in teach is partial. The participation of course in teach is partial and the participation of instructor in teach is partial. C