工具变量的美妙之处在于它们让我们以新的视角看世界。
I don't care if you're black, white, straight, bisexual, gay, lesbian, short, tall, fat, skinny, rich or poor. If you're nice to me, I'll be nice to you. Simple as that.
人生短暂,不要在消极上浪费时间。
I must learn to be content with being happier than I deserve.