如图，抛物线$y=-\frac{1}{2}{x}^2+bx+c$与x轴分别相交于点A（﹣2，0），B（4，0），与y轴交于点C，顶点为点P．

    Alice was very worried about her dad. For some time now she had noticed he was 1 his hair. One day, she asked him, “Daddy, every day you have less hair.2 is that?” Her father smiled and said, “It's the hair thief. He visits my head during the night when I'm 3. One by one he 4 out my hair, as much as he likes.”

    This worried Alice but she was 5 to help her father. That very night she stayed 6 as long as she could. When she was 7 her dad and mom had fallen asleep, she took a hammer and went straight to their bedroom. She walked carefully in order not to make any 8. She didn't want the hair thief to hear her. Then she began carefully 9 her father's head. When she arrived at her father's side, she began looking at his head,10to catch the hair thief as soon as he appeared. Before long, she saw a shadow on it and 11 all her strength, she swung the hammer down.

    Thwack! Her father 12a loud cry. The lump(肿块) on his head was big and growing.13 with shock, he turned the light on and saw Alice waving her hammer in the 14 with her hands. “Daddy, I 15 got him. I thought I 16 him, but it looks like he escaped!” said Alice. At the same time, the mother woke up. She 17laughing when she knew what had happened.

    So Alice's father had to 18to her that the hair thief didn't exist, and that losing hair is something that just happens 19 to most daddies. And Alice still worried about her daddy, but she no longer waited for the hair thief.20 , she bought her daddy a very nice sleeping hat.

漫画《合力》形象地表明（    ）

①人民民主专政的本质是人民当家作主

②民主与专政是密不可分的

③坚持人民民主专政是社会主义现代化建设的政治保证

④在新时期，国家的中心任务就是依法惩治腐败

图一 明中后期棉花图·收贩

图二 明代工商业城市分布图

图三 清朝北京前门  图四 广州十三行

商业繁荣景象