一、Geocentric Theory托福听力原文： NARRATOR:Listen to part of a lecture in a history of science class. FEMALE PROFESSOR:Ok,we've been talking about how throughout history,it was often difficult for people to ...

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Only Slate Plus members can gift Slate stories. Become a member to share 10 free articles a month. It might seem hard to believe, at first, that people can navigate using such a seemingly complicated ...