"好吧，我们必须确保安全，只能有一个人留守了。"
无奈，执勤民警只得留一名辅警留守。[{'character': '无', 'pinyin': 'u2', 'highest pitch': 9.0, 'lowest pitch': 7.8, 'duration': 0.14, 'prosody hierarchy': 'null'}, {'character': '奈', 'pinyin': 'nai4', 'highest pitch': 10.38, 'lowest pitch': 7.73, 'duration': 0.33, 'prosody hierarchy': '#3'}, {'pinyin': 'sp1', 'highest pitch': 0.0, 'lowest pitch': 0.0, 'duration': 0.15}, {'character': '执', 'pinyin': 'zhiii2', 'highest pitch': 9.77, 'lowest pitch': 9.04, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '勤', 'pinyin': 'qin2', 'highest pitch': 9.85, 'lowest pitch': 9.58, 'duration': 0.18, 'prosody hierarchy': '#1'}, {'character': '民', 'pinyin': 'min2', 'highest pitch': 10.48, 'lowest pitch': 8.51, 'duration': 0.21, 'prosody hierarchy': 'null'}, {'character': '警', 'pinyin': 'jing3', 'highest pitch': 10.3, 'lowest pitch': 4.11, 'duration': 0.32, 'prosody hierarchy': '#2'}, {'character': '只', 'pinyin': 'zhiii2', 'highest pitch': 9.77, 'lowest pitch': 7.36, 'duration': 0.17, 'prosody hierarchy': 'null'}, {'character': '得', 'pinyin': 'dei3', 'highest pitch': 8.42, 'lowest pitch': 6.22, 'duration': 0.13, 'prosody hierarchy': 'null'}, {'character': '留', 'pinyin': 'liou2', 'highest pitch': 7.72, 'lowest pitch': 5.75, 'duration': 0.19, 'prosody hierarchy': '#1'}, {'character': '一', 'pinyin': 'i4', 'highest pitch': 7.84, 'lowest pitch': 7.38, 'duration': 0.11, 'prosody hierarchy': 'null'}, {'character': '名', 'pinyin': 'ming2', 'highest pitch': 8.69, 'lowest pitch': 6.28, 'duration': 0.22, 'prosody hierarchy': '#2'}, {'character': '辅', 'pinyin': 'fu2', 'highest pitch': 10.28, 'lowest pitch': 7.23, 'duration': 0.23, 'prosody hierarchy': 'null'}, {'character': '警', 'pinyin': 'jing3', 'highest pitch': 10.3, 'lowest pitch': 5.82, 'duration': 0.19, 'prosody hierarchy': '#1'}, {'character': '留', 'pinyin': 'liou2', 'highest pitch': 7.72, 'lowest pitch': 5.58, 'duration': 0.19, 'prosody hierarchy': 'null'}, {'character': '守', 'pinyin': 'shou3', 'highest pitch': 6.64, 'lowest pitch': 3.7, 'duration': 0.37, 'prosody hierarchy': '#4'}]