user: Question: If the date is 7-21-2006, who was the opponent?
Columns: ['Edition', 'Round', 'Date', 'Against', 'Surface', 'Opponent', 'Result', 'Outcome']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['2005 Europe/Africa Zone Group II', '1R', '3-04-2005', 'Ivory Coast', 'Hard (I)', 'Valentin Sanon', '6–4, 6–4, 7–5', 'Win']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Date" = '7-21-2006';