user: Question: What team lost on 20 August 1989?
Columns: ['Season', 'Cup FinalDate', 'WinningTeam', 'Score', 'LosingTeam', 'Cup Final Attendance']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1977', '9 October 1977', 'Brisbane City (1)', '1–1 (5-3 Penalties)', 'Marconi Stallions', '9,000']
SQL:

assistant: SELECT "LosingTeam" FROM "Table" WHERE "Cup FinalDate" = '20 August 1989';