Robots capable of social engagement help with loneliness as well as cognitive functioning, but the robot itself doesn't have to engage directly—it can serve as an intermediary for human communication.
2018年12月六级真题(第二套)阅读 Section C
柯林斯高阶英汉双解学习词典释义
N-COUNT
调解人;中间人
An intermediary is a person who passes messages or proposals between two people or groups.