It could be they trust each other, although if you trust a crook that's not?

可能他们互相信任,但你信一个罪犯吗

耶鲁公开课 - 博弈论课程节选

Could you tell us about a person who wrote a recommendation letter for you?

你能给我们介绍一位给你写推荐信的人吗？

写推荐书的人 - SpeakingMax英语口语达人