know-nothing

I know nothing at all about the recent happenings there.

对那里来发生的事一点儿也不知。

This might seem very perplexing to those who know nothing about it.

这对那些对它一无所知的人来说可能显得很难理解。

He knows nothing of unprofessional matters.

与专业无关的事, 他什么也不知。

I hasten to add that I knew nothing of the fraud at the time.

不迭地补充说，当时对那个骗局一无所知。

However, we can know nothing through this process about the "numina" (inward realities) of nature.

但是，在这一过程中，们对自然界的“numina”（内在现实）依然毫无所知。

He closed up when he found he knew practically nothing about the subject under discussion.

当他发现自己对所讨论的问题实际上一无所知时, 就不再开口了。

I know nothing but Wikipedia is a cyclopedia which is easy to use,free and grow continuously.

只知维基是一个非常好用的，免费的，不断成长的百科全书。