题目

在平直公路上，甲、乙两汽车同向匀速行驶，乙在前，甲在后。某时刻因紧急避险，两车司机听到警笛提示，同时开始刹车，结果两车刚好没有发生碰撞。如图所示为两车刹车后运动的v－t图象，以下分析正确的是() A . 甲刹车的加速度的大小为0.5m/s2 B . 两车刹车后间距一直在减小 C . 两车开始刹车时的距离为87.5m D . 两车都停下来后相距12.5mWhen the teacher came in, he ________ with others. A. was seen talking B. was seen to talk C. saw to talk D. saw talk