运用神机的人，众人不知道他的功劳，在明处争斗不休的人，众人却都知道他。
The great secret that all old people share is that you really haven't changed in seventy or eighty years. Your body changes, but you don't change at all. And that, of course, causes great confusion.
Profitability and sustainability are not mutually exclusive—they must go hand in hand.
