user: Question: What team was the opponent when the round was SF?
Columns: ['Date', 'Round', 'Opponent', 'Venue', 'Result', 'Attendance', 'Scorers']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['4 January 1997', 'R3', 'West Bromwich Albion', 'H', '3–0', 27446.0, 'Wise , Zola , Burley']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Round" = 'SF';