题目

( )A. My sister often reads newspapers to old people.B. My sister often helps old people to carry water.C. My sister often helps old people to clean the room. 答案：【答案】A【解析】选项A我姐姐经常给老年人读报纸。选项B我姐姐经常帮老年人提水。 选项C我姐姐经常帮老年人打扫房间。图片是给老年人读报纸，A与其匹配，故选A。已知圆M：x2+y2+4x﹣2y+3=0，直线l过点P（﹣3，0），圆M的圆心坐标是；若直线l与圆M相切，则切线在y轴上的截距是