How many submissions have been accepted?
select count(*) from acceptance where result = "Accepted"
What is the average submission score of these works?
select avg(t2.scores) from acceptance as t1 join submission as t2 on t1.submission_id = t2.submission_id where t1.result = "Accepted"
Which submission has the highest score? Show its submission ID.
select t2.submission_id from acceptance as t1 join submission as t2 on t1.submission_id = t2.submission_id order by t2.scores desc limit 1
How about its submission result?
select t1.result from acceptance as t1 join submission as t2 on t1.submission_id = t2.submission_id order by t2.scores desc limit 1