题目

He has been in bed ______ he fell off his bike a week ago. A . even if B . soon after C . now that D . ever since 答案：D如图，□AOBC的对角线交于点E，反比例函数(x>0)的图像经过A、E两点，若□AOBC的面积为9，则k=  ▲ ．