A

    A king loved music. One day, a man 1 the king a harp (竖琴). When the king played it,   the harp sounded terrible. Many people tried it. They agreed that the harp was useless. It was thrown out as rubbish.

    A little girl found the harp. She didn't know how to 2 it. She decided to have a try. She played day and night. The music was never perfect,  3 each time it sounded a little better.

    One day, the harp started to produce beautiful music. In fact, it was a 4 harp. It could be played well by someone if he put in enough effort (努力).

    The king called the girl to the palace. When he saw that she was playing the old harp. He was filled with joy. He made the girl his own private 5.

分解因式：2x²﹣4x=____．

已知定义在R上的函数f(x)满足f(2)=1，且f(x)的导函数f'(x)>x-1则不等式$f\left(x\right)<\frac{1}{2}{x}^2-x+1$的解集为（    ）