投资就是低买高卖，相当简单。问题是要知道什么是低，什么是高。

PAC学习框架提供了一种正式的方法来分析学习算法的效率和有效性。

The house,the stars,the desert,what givethem their beauty is something that is invisible.

I don't let negativity bring me down.

性别平等的未竟事业是我们这个时代的决定性挑战之一。

The highest virtue is to become like God.

The fundamental point in fabricating a chain reacting machine is of course to see to it that each fission produces a certain number of neutrons and some of these neutrons will again produce fission.

Number is the ruler of forms and ideas.

电影是展示不可见之物的艺术。