题目

The taxi ________ I usually took to my office was destroyed in a traffic accident? A．in which         B．by which         C．which       D．with which 答案：C 解析: 略函数y=x2(x>0)的图像在点(ak,ak2)处的切线与x轴交点的横坐标为ak+bk为正整数，a1=16，则a1+a3+a5=____ _____