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.
2018年6月四级真题（第三套）阅读 Section B
英语六级真题
As they walk around a playground or other area, text, video or audio pops up at various points to help them try to figure out why aliens were in the schoolyard.
出自-2013年6月阅读原文
柯林斯高阶英汉双解学习词典释义
ADJ
音频的；声音的
Audio equipment is used for recording and reproducing sound.