题目

一辆汽车以20 m/s的速度做匀速直线运动,发现前方有障碍物，立即刹车，刹车的加速度大小为5 m/s 2,则汽车刹车后第2 s内的位移和刹车后5 s内的位移为( )A. 30m 40m B. 30m 37.5m C. 12.5m 40m D. 12.5m 37.5m 答案：【答案】C【解析】 This afternoon I'll attend a lecture ________ Japanese culture, including the art of tea-making and flower-arranging． [　　] A．on B．about C．in D．of