zhufubang012 看绝望的主妇学英语俚语：Play it by ear
Play it by ear: To improvise; to act as the situation requires, without advance planning（随机应变，见机行事）. This term for playing instrumental music without reading the notes from a score, but simply going by the sound, dates from the seventeenth century. It was not transferred to other kinds of improvisation until the mid-twentieth century.
中文释义：俚语“play it by ear”源于音乐，指不用看乐谱凭耳朵和记忆就能弹奏出乐曲。现在这个短语的意思可以引申为“根据事情的发展情况来决定下一步怎么做”，也就是“见机行事、边走边看”的意思。例句： Facing the tricky enemy, he had to play it by ear.（面队狡猾的敌人，他只有随机应变了）。引申其他和“ear”相关的俚语：chew one’s ear off（美国俚语，表示“教训、训斥”）；give one’s ears（不惜任何代价（得到或做某事））；wet behind the ear（“缺乏经验”、“乳臭未干”）。
