题目

He spoke loudly ____ the audience could hear him clearly. A. so                        B. that             C. so that          D. in order to 答案：C直线y=-2x-4与x轴交于点A，与y轴交于点B，将线段AB绕着平面内的某个点旋转180°后，得到点C、D，恰好落在反比例函数的图象上，且D、C两点横坐标之比为3：1，则k=    ．