a. Find the titles of courses in the Computer Science department that have 4 credits.

b. Find the IDs of all students who were taught by an instructor named Lawrence; make sure there are no duplicates in the result.

c. Find the average salary of Computer Science department instructors.

SQL

student ID nattie takes ID sec id dept name tot cred semester vear grade section course id sec id course course id title credits department advisor semester- building building budget ar time_slot time slot id start time end_time room no time slot id instructor ID name dept name salary prereg classroom building TOOm no teaches ID sec id capacity L semester