Consider the following relations: student$($SID$,$Name$),$ course$($CID$,$CName,DeptName$),$

took$($SID$,$CID,Year$).$ The student relation has SID as its sole relation key and gives the

names of students. The course relation has CID as its sole relation key; its tuples

indicate the names of the courses and the names of the departments offering the

courses. The took relation contains tuples indicating who have taken which courses

in which year; SID,CID