"Randomized experiments are the gold standard for causal inference, but they are not always feasible."

生存的规则永远不会改变，无论你是在沙漠中还是在市中心的街道上：你需要水分，你需要食物，你需要庇护所。

"What good is the warmth of summer, without the cold of winter to give it sweetness."

材料即信息。

人生就像一首歌，有高潮也有低谷，重要的是如何演绎。