user: Question: Which opponent had an attendance of 40,070?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Record', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'September 12, 2004', 'Arizona Cardinals', 'W 17-10', '1-0', '65,538']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Attendance" = '40,070';