generate response: I'll be heading to Cambridge, but I can't leave until sometime after 21:15, please.. Intent: find_train. Slots: train-day=friday, train-departure=kings lynn, train-destination=cambridge, train-leaveat=21:15
Response: There are two trains meeting your needs. The earlier train leaves at 22:11 and the later train at 23:11. The ride takes 47 minutes. Which do you want me to book?