Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What circuit was used on August 21?

### Inputs:
table_name: table, columns: ['Round', 'Circuit', 'Location', 'Date', 'Pole position', 'Fastest lap', 'Winning driver', 'Winning team', 'Supporting']

### Response:
SELECT Circuit FROM table WHERE Date = August 21