user: Question: What is the Opponent of the game in 1989?
Columns: ['Outcome', 'Date', 'Championship', 'Surface', 'Opponent', 'Score']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['Winner', 1981.0, 'Johannesburg , South Africa', 'Hard', 'Bernard Mitton', '6–4, 6–4']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Date" = 1989.0;