The big cats once roamed throughout Asia, into Siberia, but conservationists say only a few thousand tigers remain in the wild;

VOA: standard.2010.02.22

There we go. Now if I do this, an infinite number of times, we should get roughly 50/50, but now we have the ability to do things only once in awhile.

开始，如果我们，不停地按这个按钮，我们大致会有一半的机会听到猫叫，但是我们每次只有一次按按钮的机会。

哈佛公开课 - 计算机科学课程节选

But once having been cultivated and educated, people will see, not only see the difference between higher and lower pleasures, but will actually prefer the higher to the lower.

但他同时认为，人一旦接受教育和培养，就应该不仅能区分高级和低级快乐，而且会真的更偏好高级快乐。

耶鲁公开课 - 公正课程节选