题目平面内,一个点到圆的最大距离为9cm9cm9cm,最小距离为5cm5cm5cm,则圆的半径为( )A.14cm14cm14cm或4cm4cm4cmB.7cm7cm7cm或2cm2cm2cmC.7cm7cm7cmD.2cm2cm2cm知识点:圆与圆的位置关系章节:第31章 圆 / 31.2 点和圆、直线和圆的位置关系