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

### Instruction:
Which circuit has two heats as the format?

### Inputs:
table_name: table, columns: ['Rd.', 'Circuit', 'City / State', 'Date', 'Format', 'Round winner', 'Car', 'Entrant']

### Response:
SELECT Circuit FROM table WHERE Format = Two heats