我爱她是违背常理，是妨碍前程，是失去自治，是希望破灭，是断送幸福，是注定要尝尽一切的沮丧和失望的。可是，一旦爱上了她，我再也不能不爱她。

There are two ways to extend a business. Take inventory of what you are good at and extend out from your skills. Or determine what your customers need and work backwards, even if it requires learning new skills.

相关系数的可能误差不是一个固定的量，而是取决于样本的大小。