Our TV set sell well, but ten years ago no one could have imagined such a big share in the market that they______.
A:were to have
B:had had
C:were having
D:had
72×4=____
如图,在平面直角坐标系中,已知点A坐标为(2,4),直线x=2与X轴相交于点B,连结OA,抛物线y=x2,从点O沿OA方向平移,与直线x=2交于点P,顶点M到A点时停止移动.(1)求线段OA所在直线的函数解析式;(2)设抛物线顶点M的横坐标为m,①用m的代数式表示点P的坐标;②当m为何值时,线段PB最短;(3)当线段PB最短时,相应的抛物线上是否存在点Q,使△QMA的面积与△PMA的面积相等,若存在,请求出点Q的坐标;若不存在,请说明理由.
读下图 “我国四大地理区域图”,完成下列要求。