user: Question: Which nation has a heat of 4, and is ranked 8?
Columns: ['Rank', 'Heat', 'Cyclist', 'Nation', 'Result']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 3.0, 'Rebecca Romero', 'Great Britain', '3:27.703']
SQL:

assistant: SELECT "Nation" FROM "Table" WHERE "Heat" = 4.0 AND "Rank" = 8.0;