社会系统是个人与个人之间、群体与群体之间关系的网络。
真相如同太阳;你可以暂时遮蔽它,但它不会消失。
Exceed your customers' expectations. If you do, they'll come back over and over. Give them what they want — and a little more.
在没有其他信息的情况下,参数的最佳估计是其样本值。