After the top leader of the Communist Party of China in 2013, Xi Jinping urged Chinese officials to give up their waste-generating habits. A. elected B. electing C. being elected D. to be elected 答案:C电火花打点计时器,是一种使用交流电源的计时仪器,工作电压为220V,当电源频率为50Hz时,它每隔 s打一次点。下图是某同学研究匀变速直线运动的一条实验纸带,A、B、C、D、E为计数点,相邻两计数点之间还有四个点未标出,由于C点不够清晰,只量得三个数据如图所示,则此小车运动的加速度为 m/s2,C点的速度的大小等于 m/s。