student takes ID course id sec id ID namme dept name tot cred year grade section course department dept name building budget advisor sec id title t name credits s id i_id time slot uilding roomno time_slot id day start time end time instructor ID tame dept name salary prereg classroonm IO capacity eaches ID course id year Express answers to 3-9 in relational algebra. Your queries should NOT include unneeded relations. . What is the difference (if any) between the following three queries? | |course-d, sec lcourse id. see id(O semesier- "Spring" A year - 2019 (takes)) lcourse id, sec id(O semester- "Spring" A year 2019 (teaches)) id( semester-*Spring."A year-2019 (section )) Why does the following query fail to list all of the students who have taken/are taking a course taught by Jeremy Blum? b. student name, student. ID( student D, takes D, teaches name-"Jeremy Blum" (instructor)) Write three queries- one using only cross products, one using only theta joins, and one using only natural joins - to find the names of all students who received an A in the course with the title Database Design C