脑和脊髓组成人的中枢神经系统，其中大脑是脑的重要组成部分，大脑表面的____ 内有多种生命活动的功能区。

通读全文, 根据短文理解, 选择正确答案填空。

    If you are given only 1 yuan, can you live in a city for one day? It may be a little difficult. But 1 from Xi'an did it.

    On April 10^th, more than 60 students from the Middle School Attached to Northwestern Polytechnical University 2 the One Yuan Metropolis Survival. The charity for teenagers called Imperceptible Education held this 3  .  Students had to live and they had to deal with a lot of  4  tasks. It has happened in eight cities and is going to four others, including Beijing, in May.  

    To  5  , many students looked for part-time jobs and saw how hard life was. Zhang Qiyue, 14, asked more than 10 restaurants for a job and 6   got one chance. "We were sad when they said   7  . But slowly, we got used to it," he said. After being a waiter for an hour, he 8   25 yuan.

    Some made use of their talents  9  singing and dancing in parks or shopping malls. Many people who walked by took notice and helped   10  . Zhao Jiacheng, 14, drew pictures and made paper crafts （手工）. "This showed it's  11 to learn a special skill," he said.

    Living was hard,    12 finishing the tasks was not any easier. They went to different places to finish tasks in a  13  time. The most amazing one was when they had to exchange things worth a hundred yuan with only a piece of paper in half an hour. "We learned  14   to persuade （说服） others. From a balloon to a cake to a bottle of yogurt……, after almost 20 tries, we got an expensive necklace, "he said, "we would   15 all of the money we had raised to poor schools in Tibet."