不过事实上人人都知道吸烟有害健康，因此在烟草行业这不算什么问题。但是如果一个产品的危害不被大众所知道时，那这就将成为一个问题了。

Now in fact everyone knows about the dangers of smoking, so that is not a serious problem; but it is a problem when the hazards of a product are not widely known.

youdao

如果你不知道的周围的形势，不知道怎么保护你的钱包不被扒手光临，或傻傻地想当然，认为自己的钱有多么安全，那你就是一个非常容易被盯上的目标。

If you don't know your way around, don't know how to protect yourself from pickpockets, or make silly assumptions about how safe your money is, you can become an easy target.

youdao

但是，病毒知道他们的宿主- - -它们可以不被发现的侵入细胞，关掉警报系统，削弱细胞决定自身基因表达的权威。

But viruses know their hosts well-they can break into cells undetected, switch off alarm systems, and undermine the cell's authority in deciding which genes get expressed.

youdao

Now I don't know how impressed you are, the year before that it was 22% in one year.

我不知道给你们是否被震撼到了,前年的收益率是22%

耶鲁公开课 - 金融市场课程节选

We have this suspense, as I say, between expectation, the possibility of violation, and simply not knowing.

我们有这么一个悬念，正如我所说的，在期望和期望被违背的可能性之间，而且我们完全不知道。

耶鲁公开课 - 文学理论导论课程节选

And they walk significantly slower toward the elevator, not knowing that they were primed with old words.

走向电梯的速度明显慢，虽然不知道自己被与“老“相关的字影射过。

哈佛公开课 - 幸福课课程节选