以下是引用mariezhu在2004-3-26 9:35:00的发言: 个人感觉看没看到layers of sediment与个人能力无关,所以be able to是第一眼就该排除的选项。 一家之言,open to discussion.... 感谢bluestonel提供的这个知识点,whenever a pronoun has more than one possible antecedent (the thing it refer to), it's used incorrectly 以后我会在做题时加以验证。