题目

—I feel terrible. I didn't do well in the math test.—_______. You're already making progress and will surely learn it well. A . Don't dream away your time B . Don't take things for granted C . Don't put the cart before the horse D . Don't take it too hard 答案：D（2009•庆阳）如图，在平面直角坐标系中，将一块腰长为的等腰直角三角板ABC放在第二象限，且斜靠在两坐标轴上，直角顶点C的坐标为（-1，0），点B在抛物线y=ax2+ax-2上（1）点A的坐标为______，点B的坐标为______；（2）抛物线的关系式为______；（3）设（2）中抛物线的顶点为D，求△DBC的面积；（4）将三角板ABC绕顶点A逆时针方向旋转90°，到达△AB′C″的位置．请判断点B′、C″是否在（2）中的抛物线上，并说明理由．