2018年四级阅读关于高等教育收费作业系统的文章：
A Pearson spokesperson told BuzzFeed News that "digital materials are less expensive and a good investment" that offer new features, like audio texts, personalized knowledge checks and expert videos.
这里有两个that，分别就在直接引语的开始和结束的地方。第二个that引导的应该定语从句吧？它的先行词可以是直接引语的digital materials吗？或者说第二个that引导的从句如何理解？
这里that作主语引导定语从句，先行词为digital materials. 由于定语从句比较长，假如放在前面和主句连在一块容易产生歧义，也不合乎尾重原则，因此此时需要把定语从句后置，语法上称为“分割式定语从句”，这种现象在英语里非常容易见到。比如：
Tidal sites have already been identified that will produce one sixth or more of the UK's power——and at prices competitive with modem gas turbines and undercutting those of the already ailing nuclear industry.
