如果你都达到了99%的预期，就是“很靠近”了，不必再继续了.
This is true! Though “一尺之锤，日取其半，万世不竭。” is theoretically correct, but is not practically doable. Even design has no upper limit, if you reached the goal of 99%, then, there would be no significant improvement after a 99.9% goal being achieved.
