题目

—The information is very important. You should _______.       —Thank you. I will. A. write it down   B. write them down   C. write down it   D. write down them 答案：A13．已知同一平面内存在⊙O和点P，点P与⊙O上的点的最大距离为8，最小距离为2，则⊙O的半径为3或5．