题目

以A(－2,1)、B(4,3)为端点的线段的垂直平分线的方程是( ) A．3x－y＋5＝0 B．3x－y－5＝0 C．3x＋y－5＝0 D．3x＋y＋5＝0 答案：[答案] C [解析] kAB＝，AB中点坐标为(1,2)， 故所求直线方程为3x＋y－5＝0.You used to be a top student. You shouldn’t ___________.A．worry about not getting a good jobB．worried about you’ll not get a good jobC．worry about not get a good jobD．worry about having a good job