i need a train that departs from cambridge and arrives at london liverpool street . can you help me ?
{'service': 'train', 'act': 'request', 'slot_name': 'leave', 'value': '?'} {'service': 'train', 'act': 'request', 'slot_name': 'day', 'value': '?'}
i would be happy to . do you have a specific date and time for your departure ?