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

### Instruction:
What type of surface was used for the carthage tournament on august 14, 1994?

### Inputs:
table_name: table, columns: ['Date', 'Tournament', 'Surface', 'Opponent in the final', 'Score']

### Response:
SELECT Surface FROM table WHERE Tournament = carthage AND Date = august 14, 1994