1 [U] [sing] knowledge (of/about sth) information, understanding and skills that you have gained through learning or experience 知识 [sing]
I have a working knowledge of French (= enough to be able to make myself understood).我的法语达到了可沟通的地步。
2 [U] the state of knowing about a particular fact or situation 知晓;了解;熟悉:
To my knowledge (= from the information I have, although I may not know everything) they are still living there.据我所知,他们依然住在那儿。She did it without my knowledge (= I did not know about it).这件事她是背着我干的。
be common/public knowledge to be sth that everyone knows 成为人尽皆知的事