They did so because they knew the world was watching.

他们之所以敢于这样做，因为他们知道全世界都在注视着这里。

youdao

By the late 15th century most educated Europeans knew the world was round.

到了15世纪末，大多数受过教育的欧洲人都知道地球是圆的。

youdao

I knew we were intertwined, I knew the world was flat, but what I've really learned is just how flat it's become.

我早就知道所有人都密不可分，也知道世界是平的，但我真正学到的是，世界竟然已变得这么平。

youdao

I knew the sound well. Many a night,late at night, when all the world slept, it has welled up from deep within my own chest.

VOA: special.2009.05.16

The team knew that the world is filled with mobile phones.

VOA: special.2009.02.02

I do not hold any animosity. But I tell Obasanjo today, and I am sure he knows it, that he lied to the world when he said that I was escaping and he knew nothing about it.

VOA: standard.2009.11.10

OPEC's meeting in Vienna on March 27th knew the world's eyes were on them.

ECONOMIST: Slick OPEC

And yes I knew the world is already crammed with days for far more worthy causes than our relationship with music.

BBC: RELATED BBC SITES

The second son of Nelle and Jack Reagan first knew the world as a place of open plains, quiet streets, gaslit rooms and carriages drawn by horse.

CNN: President Bush: 'Our whole nation grieves'