He kept a running tally of who had called him, who had visited, who had sent flowers.

他记录着关于谁给他打过电话、谁看望过、谁送过花的一本流水账。

《柯林斯英汉双解大词典》

Who knows who is who?

谁知道谁是谁？

youdao

In 'the man who came', 'who' is a relative pronoun and 'who came' is a relative clause.

在the man who came中，who是关系代词，而who came是关系从句。

《牛津词典》

The medical experts agreed with doctors who say that people who know they lack a vitamin should take vitamin supplements.

VOA: special.2009.04.21

Remember I asked you from the preface, John Ray's preface, to figure out who Dolly Schiller is, who dies in childbed.

还记得我曾让你们找出约翰·雷序言中的，死在产床上的多莉是谁。

耶鲁公开课 - 1945年后的美国小说课程节选

I've never played World of Warcraft, for example, but I have a lot of friends who do and who still do.

比如说，我从来不玩魔兽世界，但我有很多朋友玩，他们现在还在玩。

电子游戏 - SpeakingMax英语口语达人

It's also those who are behind the killers, those complicit with them, who are punishable.

BBC: [an error occurred while processing this directive]

My bankers, the people who make loans to me, are guys who I have relationships with.

NPR: Gulf Banks Vie to Help Hurricane Victims

We have candidates who have been around a long time, who have played major roles in Congress.

NPR: Presidential Candidates Target Black Music Festival