题目解析:
dispute: 争辩,undisputed: 无可辩驳的,毫无疑问的。所以C的acknowledged(广为承认的)正确。A是神秘的;B是意外的,出乎意料的;D是重大的,有意义的。对应原文:The undisputed pre-Columbian presence in Oceania of the sweet potato, which is a New World domesticate, has sometimes been used to support Heyerdahl’s “American Indians in the Pacific” theories.原文说一个什么样的证据能够用来支持某人的理论,AB明显不靠谱,significant貌似正确,但是和dispute的意思毫无关联,也不对。