CREATE TABLE acceptance (submission_id NUMBER, workshop_id NUMBER, result CLOB)
CREATE TABLE workshop (workshop_id NUMBER, date CLOB, venue CLOB, name CLOB)
CREATE TABLE submission (submission_id NUMBER, scores NUMBER, author CLOB, college CLOB)

Show the colleges that have both authors with submission score larger than 90 and authors with submission score smaller than 80.
SELECT college FROM submission WHERE scores > 90 INTERSECT SELECT college FROM submission WHERE scores < 80
SELECT "college" FROM "submission" WHERE "scores" > 90 INTERSECT SELECT "college" FROM "submission" WHERE "scores" < 80