题目

He began ___________ in magazines in 2001. A . having articles publishing B . having articles publish C . having articles published D . having articles to publish 答案：C汽车正在以10m/s的速度在平直的公路上匀速前进，在它的正前方S0处有一辆自行车以 4m/s的速度做同方向的匀速直线运动，汽车立即关闭油门做a =-6m/s2的匀变速运动，若汽车恰好碰不上自行车，则S0的大小为A.8.33mB.3mC.3.33mD.7m