user: Question: Name the surface for 20 March 2007
Columns: ['Date', 'Tournament', 'Surface', 'Opponent in the final', 'Score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['19 November 2002', 'Berri', 'Grass', 'Paul Baccanello', '6–2, 6–2']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Date" = '20 March 2007';