what sort of dining does cambridge offer in the centre , in the moderate price range ?
{'service': 'restaurant', 'act': 'request', 'slot_name': 'food', 'value': '?'} {'service': 'restaurant', 'act': 'inform', 'slot_name': 'choice', 'value': '21'}
there are 21 different choices . what kind of food are you looking for ?