"Matching methods can be a powerful tool when randomization is not possible."
当随机化不可行时,匹配方法可以是一个强大的工具。
The best way to predict the future is to create it.
办丧事虽有一定的礼仪,但还是以哀痛为本。 
In the end, we will remember not the words of our enemies, but the silence of our friends.
意志不坚强的,智慧一定不高;说话不讲信用的,行动也不会果敢;拥有财富而不肯分给人的,不值得和他交友;守道不坚定,阅历事物不广博,辨别是非不清楚的,也不值得和他交游。
"In quantum mechanics, the act of observation changes the system being observed."