[{'role': 'USR', 'utterance': 'Can I have a look at that digital camera please?'}
 {'role': 'SYS', 'utterance': 'Yes of course. This is a really good one actually.'}
 {'role': 'USR', 'utterance': 'How much does it cost?'}
 {'role': 'SYS', 'utterance': 'This one is 1500 yuan.'}
 {'role': 'USR', 'utterance': "It looks pretty good. I think I'll take it."}]
{'role': 'SYS', 'utterance': 'Would you like anything else?'}