In SQL

users(email, name, pwd, city, gender)

products(pid, descr)

sales(sid, lister, pid, edate, descr, cond, rprice)

bids(bid, bidder, sid, bdate, amount)

items(sid, no, pid, descr)

reviews(reviewer, reviewee, rating, rtext, rdate)

previews(rid, pid, reviewer, rating, rtext, rdate)

For users who have received at least 3 reviews, find the email and the average review rating. Limit the result to only top 5 users with the highest average review ratings, and sort the results in a descending order of average review ratings. Hint: check out the limit function in Sqlite.