0 to make someone unconscious, especially in boxing -- （尤指拳击中）击倒（对手）
That flu really KO'd me for a while. 流感着实把我打到了一阵子。
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
再长的路，一步步也能走完，再短的路，不迈开双脚也无法到达。
