The writer must be able to superintend himself and criticize himself.

But only in their dreams can men be truly free，Twas always thus,and always thus will be.

成功不仅仅是赚钱，而是有所作为。

Don't just sell products—sell values and vision.

The first duty of a man is to think for himself.

两个物体的相互作用力总是大小相等，方向相反，同时出现或消失且作用于同一直线上。