起源与拳击运动.在拳击场上,将对方打倒而致胜,叫做konck-out,简称KO,或写成一字kayo,可用做名词:He won by a K.O.、动词:The champ K.O.’d him in the third round）,或形容词:That was a K.O.punch,如未打倒而对方...