Table: steeler_1989
Columns: week
date
opponent
location
time_et
tv
result
record

Question: Who was the opposing team played at Riverfront Stadium?
SQL: SELECT "opponent" FROM steeler_1989 WHERE "location" = 'Riverfront Stadium'

Question: How many days were the Kansas City Chiefs the opposing team?
SQL: SELECT COUNT("date") FROM steeler_1989 WHERE "opponent" = 'Kansas City Chiefs'