All I know about him is that he was 17 years old and that he and his family gave me a second chance at life.

对于他，我只知道他有17岁以及他和他的家人给了我第二次生命。

youdao

Little do I know about him.

我对他所知极少。

youdao

I know about him.

我知道他的情况。

youdao

I just happened, while I was a graduate student at Oxford University, to meet somebody who is vegetarian and start talking to him about the way we treat animals which I really didn't know much about.

那时我还在牛津攻读硕士研究生,偶然遇到了一个素食者,我们聊到人类是怎样对待动物的,当时我的确不是很了解。

普林斯顿公开课 - 人性课程节选

All that I know about him is that he was from Sheffield, was 29 years old and died in a road accident.

BBC: NEWS | UK | How organ donations can change lives

Let me tell you what I know about him.

CNN: Clinton: Time again to choose a more perfect union

Let me say a final word about your son's condition -- again recognizing that I know nothing about him beyond what's in your question.

CNN: How can I help my despairing son?