这个主意挺好的，我们可以考虑免费提供垃圾分类桶。
免费垃圾分类桶怎么样？[{'character': '免', 'pinyin': 'mian3', 'highest pitch': 8.32, 'lowest pitch': 6.91, 'duration': 0.23, 'prosody hierarchy': 'null'}, {'character': '费', 'pinyin': 'fei4', 'highest pitch': 9.73, 'lowest pitch': 7.33, 'duration': 0.16, 'prosody hierarchy': '#1'}, {'character': '垃', 'pinyin': 'la1', 'highest pitch': 9.62, 'lowest pitch': 8.6, 'duration': 0.21, 'prosody hierarchy': 'null'}, {'character': '圾', 'pinyin': 'ji1', 'highest pitch': 10.01, 'lowest pitch': 9.02, 'duration': 0.15, 'prosody hierarchy': '#1'}, {'character': '分', 'pinyin': 'fen1', 'highest pitch': 10.71, 'lowest pitch': 9.58, 'duration': 0.16, 'prosody hierarchy': 'null'}, {'character': '类', 'pinyin': 'lei4', 'highest pitch': 10.69, 'lowest pitch': 8.59, 'duration': 0.16, 'prosody hierarchy': 'null'}, {'character': '桶', 'pinyin': 'tong2', 'highest pitch': 9.66, 'lowest pitch': 6.39, 'duration': 0.27, 'prosody hierarchy': '#1'}, {'character': '怎', 'pinyin': 'zen3', 'highest pitch': 9.66, 'lowest pitch': 5.78, 'duration': 0.14, 'prosody hierarchy': 'null'}, {'character': '么', 'pinyin': 'me5', 'highest pitch': 5.78, 'lowest pitch': 5.02, 'duration': 0.13, 'prosody hierarchy': 'null'}, {'character': '样', 'pinyin': 'iang4', 'highest pitch': 6.37, 'lowest pitch': 5.36, 'duration': 0.33, 'prosody hierarchy': '#4'}]