user: Question: Which opponent has Unknown attendance, and Lost 2-0?
Columns: ['Date', 'Opponent', 'Venue', 'Result', 'Attendance']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['21 July 2006', 'Gainsborough Trinity', 'Away', 'Lost 2-1', 'Unknown']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Attendance" = 'Unknown' AND "Result" = 'Lost 2-0';