【释义】：礼节重在相互回应。送出礼遇而对方不回应，这是不合礼数的；接受了别人的礼遇却不回报，同样也是不符合礼的要求。
Markets fail when information is asymmetric or incentives are misaligned.
感激是狗才会患的病。
"I’m not playing for the records. I’m just trying to enjoy my tennis."
Hold on to your dreams, never give up, and success will come one day.
我们这个时代最大的挑战不是技术进步，而是道德进步。