向后转,大改变向后转,作大改变
about-face n 1: act of pivoting 180 degrees, especially in a military formation [syn: {about turn}] 2: a reversal in attitude or principle or point of view; "an about-face on foreign policy" [syn: {volte-face}, {reversal}, {policy change}] v 1: turn, usually 180 degrees 2: change one's mind and assume the opposite viewpoint