user: Question: what was the opposition where the field is Waldstadion during time 6
Columns: ['Week', 'Date', 'Kickoff', 'Opponent', 'Final score', 'Team record', 'Game site', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'Saturday, April 21', '3:00 p.m.', 'at Scottish Claymores', 'L 21–24', '0–1', 'Hampden Park', 16387.0]
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Game site" = 'Waldstadion' AND "Week" = 6.0;