user: Question: What's the attendance when the opponents are Cambridge United?
Columns: ['Date', 'Opponents', 'H / A', 'Result F – A', 'Attendance']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['30 July 1994', 'Dundalk', 'A', '4 – 2', 4500.0]
SQL:

assistant: SELECT "Attendance" FROM "Table" WHERE "Opponents" = 'Cambridge United';