Once there was a man named Chulong in Thailand. One day he saw a beautiful 1 when he was walking in the park. He went near it quietly and caught (抓住) it.

     " 2 do you catch me?" asked the bird.

    "I want to make money," said Chulong.

    "Nobody will 3 me because I'll lose my beauty when I'm not free." Then the beautiful bird turned into a common one.

    Chulong was unhappy.

    The bird said,“ 4 you set me free, I will tell you three simple but useful rules. I'm sure they will 5 you."

    "But how can I trust (相信) 6 ? You may fly away," said Chulong.

    "I won't," said the bird.

    Chulong set the bird free, and it sat in a tree.

    Now tell me the 7 ，said Chulong.

     “OK,” said the bird. "The first rule is never trust everything others say. The second rule is never be unhappy about 8 you don't have. The third rule is never throw away (扔掉） what you have in your hand'

    You silly bird "shouted Chulong ". Everyone knows these three rules. You cheated (欺骗）me.”

    But the bird said,"Chulong， 9 all your actions today. You had me in your hand but you threw me away. You trusted all I said. And you are unhappy about not having me. Although the rules are simple you never 10 them ". After saying this the bird flew away.

阅读课文《天上偷来的火种》选段，回答。

接着，他把火的性质、用途向人们详细地讲述一番。然后，他和人们把一些枯树枝堆在一起，又把从天上偷来的火种投放到枯枝上。顿时，熊熊的火柱冲上天空，火光映红了整个大地。人类的第一堆篝（gōu）火点燃了。

自从有了火，人类的生活发生了想象不到的变化。人们用火来烧熟食物，驱寒取暖；用火来冶（yě）炼金属，打造生产工具；还用火来驱赶凶猛的野兽。

火为人类带来了什么？

体育课上，老师一声“向前看齐”，队伍很快就排直了。实际上是每位同学前面的一位同学，如果挡住了前面所有的同学，就可使队伍站直了，这可以用____ 来解释 。

一组数据﹣1，2，3，﹣1，0的中位数和众数分别是（　　）