题目

_____ private cars are bringing us convenience, they may also cause more traffic accidents and pollution．        A．While              B．As            C．If           D．Since 答案：A甲、乙两物体从同一地点沿同方向做直线运动，运动的v-t图象如图所示，下列说法中正确的是（　　）A．在t0时刻，甲、乙两个物体相遇B．在t0时刻，甲、乙两个物体相距最远C．甲、乙两个物体相遇时v乙＜2v甲D．甲、乙两个物体相遇时v乙＞2v甲