user: Question: Who was the winner on 28 December 2007?
Columns: ['Round', 'Venue', 'Discipline', 'Date', 'Winner', 'Second', 'Third']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Düsseldorf', '0.8km F Sprint', '27 October 2007', 'Natalya Matveyeva ( RUS )', 'Marit Bjørgen ( NOR )', 'Anna Dahlberg ( SWE )']
SQL:

assistant: SELECT "Winner" FROM "Table" WHERE "Date" = '28 December 2007';