Others have seen what is and asked why. I have seen what could be and asked why not.

别人看到已存在的事实，问为什么；我看到不存在的可能，问为什么不。

youdao

Explanation: Have you ever seen a "star" drifting slowly overhead, but not known what it was?

说明：你有没有经历过这样的情景：看见一颗“星星”慢慢划过天际，你却不知道那是什么？

youdao

They do not know you - and you only know of them what you have seen and heard.

他们不了解你，你了解的他们也只是你自己看到的及从别人那里听到的。

youdao

"They have seen what happens when patients do not come in for regular check-ups or screenings because either their insurance company does not cover it, or they cannot afford insurance in the first place,".

VOA: standard.2009.10.05

But whatever your reason for being here this is in fact our introduction to Computer Science; and contrary to what you might have heard or seen or perceived in high school, odds are computer science is not quite what you imagined it to be.

但是不管你们来这儿的原因是什么,这门课介绍的都是计算机科学,可能与你们平时听到的看到的,或者在高中时所想象的恰好相反,计算机技术的优势完全不是你想象的那样。

哈佛公开课 - 计算机科学课程节选

N log N is not nearly as good as log N. As a sanity check, what algorithm have we seen that runs in log N time?

而N，log，N和log，N并不一样，我们之前探讨过的哪个算法其时间复杂度是log，N呢？

哈佛公开课 - 计算机科学课程节选

What we have not seen is leadership not from the White House and not from Congress.

FORBES: Bloomberg Blasts The NRA. Is He The Best Leader On Gun Control?

What I have not seen discussed is the entire issue of the antenna, and its placement on wireless devices.

FORBES: The iPhone 4 Antenna Unravelled

And what we have not seen from the Republicans is any movement at all on the fundamental issue here.

WHITEHOUSE: Press Briefing by Press Secretary Jay Carney,