2,-5<3, and y1>; Y2, then there are two possibilities for A and B. One is that A and B are on the left of the center line, and then x0 >；; 2. A and B are on both sides of the midline, and point A is higher than point B. When A and B are symmetrical about the midline, x0=- 1, so x0 >；; - 1