题目

Cars produce a lot of waste gas every day and pollute the air        , air pollution has become a serious problem． A．As a result            B．In the way         C．No longer             D．At the end 答案：A已知抛物线C：与圆：有一个公共点，且在处两曲线的切线为同一直线上。（Ⅰ）求；（Ⅱ）设是异于且与及都切的两条直线，的交点为，求到的距离。