我听说过它，但从未真正看过。

I've heard of it, but never actually watched it.

youdao

我从来没听说过它。展览中展出了什么？

I've never heard of it. What was on show?

youdao

我从来就没理解过它。

I never understood it.

youdao

It's one of the only compounds, there's only I think three, where the density actually goes down when it freezes.

它是我见过的，唯一一个，在降温时密度下降的化合物。

麻省理工公开课 - 固态化学导论课程节选

So I've seen it when it was bad, I've seen it when it was great, you know, I've played Little League here.

所以我看过它糟糕的样子，也见证过它美好的时刻。我在这儿也打过小联赛。

中央公园的时光 - SpeakingMax英语口语达人

So that's promising. We did, in fact, see red in our spectrum, and it turns out that that's exactly the wavelength that we see is that we're at 657 nanometers.

这是可能的，事实上，我们在光谱里看到过红色,结果它就是我们看到的在657纳米处的波长。

麻省理工公开课 - 化学原理课程节选