i need a taxi departing from tang chinese . i need to get to downing college .
ok , what is your destination ?
{'service': 'taxi', 'act': 'request', 'slot_name': 'leave', 'value': '?'} {'service': 'taxi', 'act': 'request', 'slot_name': 'arrive', 'value': '?'}
great . now i will just need a time .