We only know it exists because of its effect on the expansion of the Universe.

我们只能根据它对宇宙膨胀所起的作用来认识到它的存在。

youdao

We only know that there hasn't been any period in the history during which the world was really at peace.

我们只知道，在历史上从来没有一段时期世界是真正处于和平状态。

youdao

Others say it puts a limit on the amount we can know about the universe, since we only know what state a particle is in once it is measured.

另一些人则认为，它为我们对宇宙的认识定下了界限，因为一个粒子只有被测量了，我们才能准确知道它的状态。

youdao

"Of course,we don't know what doses they've received, but the only persons at risk of acute radiation effects are the workers."

VOA: special.2011.03.16

I think the more we think about it, the more we realize that we only know what it is if we know the system that it belongs to, which is to say, all of the things related to it which it is not. Right?

你们越仔细想这一点，就越明白，我们只有知道事物所属的符号系统,才能认识事物，所有事物都是和同一符号系统中的反面相关的？

耶鲁公开课 - 文学理论导论课程节选

We need to know not only what are the primitives, but how do we make things meaningful in that language.

我们不仅需要知道什么是基本类型，还要知道我们在那种语言中,怎样使其变得有意义。

麻省理工公开课 - 计算机科学及编程导论课程节选

"We only know the ones who are externally exhibiting symptoms, " says Ms. Sheridan.

WSJ: Will Students Take a Mental Health Test?

We only know so much about the situation in the Congo because the kind of communication that the mobile phone allows.

FORBES: "Tainted" Technology Has Seed of Conflict Mineral Solution Within

We only know they are five skulls and some bones and we also don't know if the bones are monks from the abbey.

BBC: Alfred the Great body search in Winchester church