Table: tennis_tournament_results
Columns: year
category
champion
runner_up
score

Question: Which category had a year of 1991?
SQL: SELECT "category" FROM tennis_tournament_results WHERE "year" = 1991

Question: What is the score having a runner-up of Magdalena Maleeva?
SQL: SELECT "score" FROM tennis_tournament_results WHERE "runner_up" = 'magdalena maleeva'