某同学在研究化合物P对淀粉酶活性的影响时，得到如图所示的实验结果．下列有关叙述不正确的是（　　）

中国少数民族最多的省区是    (    )

完形填空A
    Once upon a time, there was a lazy poor man living in a small house with spider webs(网) on the walls and mice running around. People1coming into such a dirty place and the poor man was lonely and2 every day. He thought he was unhappy 3poverty(贫穷).
    One day, the poor man dropped in on4wise old man and asked him for advice about5his life. The old man gave him a vase and said, "This is a magic vase6will bring you 7.
    The poor man looked at the vase 8 He wondered 9a vase in his poor house.10 ，he didn't want to throw away such a beautiful vase, so he brought it home and put it on the table. "11not right for something 12beautiful to be empty." The poor old man looked at the vase and thought. Then some flowers 13into it. That made the vase even14 "How can I have the vase next to a spider web?" he continued. At this, he started to clean the house and paint the walls. His house turned 15 a comfortable place immediately.
    The old man cheered up and he suddenly realized why he was unhappy. From then on, he worked hard and his life got better and better.

设${\left(5x-\frac{1}{\sqrt{x}}\right)}^n$的展开式的各项系数和为M，二项式系数和为N，若$M-N=240$，则展开式中x的系数为  （   ）

已知复数,则的值为                                  （  ）