题目

---Miss Li teaches(教)            English this term.       ---You’re lucky(幸运的).          is a good teacher. A. our; She      B. us; He      C. us; She       D. ours; He 答案：C   从点P（4，5）向圆（x-2）2+y2=4引切线，则圆的切线方程为    ．