题目

阅读理解。I spent an hour writing out all the invitations to my daughter's classmates.She told me who said they were coming.We spent so much time and money making gifts.“Tina would love the sunglasses，and Mike would love this pencil…” Jenny said.She helped me make cupcakes，60 of them with different colors and tastes.Everything was ready.At four，it started to rain.And it didn't seem to stop soon.“Will they come at five？” Jenny asked me.She looked worried.I was not sure，either.We sat on the sofa and waited.At 4：50，Lisa，Jenny's best friend arrived.We were both happy 已知圆：． (1) 直线过点p(1,2)，且与圆C交于A、B两点，若|AB|＝2，求直线l的方程; (2) 过圆上一动点作平行于轴的直线，设与轴的交点为，若向量，求动点的轨迹方程，并说明此轨迹是什么曲线．