立足基本国情，面对主要矛盾，建设中国特色社会主义的总任务是（　　）

    Escaping (逃) from a fire is a serious matter. Knowing what to do during a fire can save a life. It is important to know the ways you can use and show them to everyone in the family, for example, you can use stairways, roofs and fire escapes, but no lifts.
    From the lower floors of buildings, to escape through windows is possible. Learn the best way of leaving by a window with the least chance of serious injury.
    The second floor window is usually not very high from the ground. An average (平均) person, hanging from the window by the fingertips will have a drop of about six feet to the ground--about the height of an average man. Of course, it is safer to jump a short way than to stay in a burning building.
    Windows are also useful while you are waiting for help. Be sure to keep the door closed, before opening the window. Otherwise, smoke and fire may be drawn into the room. Keep your head low next to the window to be sure you get fresh air.
On the second or third floor, the best windows to escape from are those which open onto a roof (屋顶) . From the roof a person can drop to the ground more safely.

定义新运算：对于任意实数m、n都有m☆n=m²n+n，等式右边是常用的加法、减法、乘法及乘方运算．例如：﹣3☆2=（﹣3）²×2+2=20．根据以上知识解决问题：若2☆a的值小于0，请判断方程：2x²﹣bx+a=0的根的情况．