题目

（09年湖北重点中学联考文）圆的方程为，圆的方程为，过圆上任意一点作圆的两条切线、，切点分别为、，则的最小值是A．12                       B．10                          C．6                           D．5 答案：CThe man _____his coat as soon as he walked into the warm room. [     ]A. took awayB. took downC. took offD. took on