根據可行性研究估計，乘客乘坐纜車穿越波托馬克河需時約四分鐘。
[{"id": "1", "form": "根據", "pos": "ADP", "head": "3", "deprel": "case"}, {"id": "2", "form": "可行性", "pos": "VERB", "head": "3", "deprel": "compound"}, {"id": "3", "form": "研究", "pos": "NOUN", "head": "4", "deprel": "obl"}, {"id": "4", "form": "估計", "pos": "VERB", "head": "0", "deprel": "root"}, {"id": "5", "form": "，", "pos": "PUNCT", "head": "11", "deprel": "punct"}, {"id": "6", "form": "乘客", "pos": "NOUN", "head": "9", "deprel": "nsubj"}, {"id": "7", "form": "乘坐", "pos": "VERB", "head": "9", "deprel": "advcl"}, {"id": "8", "form": "纜車", "pos": "NOUN", "head": "7", "deprel": "obj"}, {"id": "9", "form": "穿越", "pos": "VERB", "head": "11", "deprel": "csubj"}, {"id": "10", "form": "波托馬克河", "pos": "PROPN", "head": "9", "deprel": "obj"}, {"id": "11", "form": "需時", "pos": "VERB", "head": "4", "deprel": "ccomp"}, {"id": "12", "form": "約", "pos": "ADV", "head": "14", "deprel": "advmod"}, {"id": "13", "form": "四", "pos": "NUM", "head": "14", "deprel": "nummod"}, {"id": "14", "form": "分鐘", "pos": "NOUN", "head": "11", "deprel": "obj"}, {"id": "15", "form": "。", "pos": "PUNCT", "head": "4", "deprel": "punct"}]