下面是几个同学在成为中学生的一些议论，说法正确的有（    ）

①赵军：在学习和日常生活中，我们要提高对自己的要求    ②肖雯：我们的目标就是考上重点高中

③张明：成为中学生我们更应增强责任感自觉性                    ④韩阳：我们要干大事，不必理会日常生活中的小事

函数的定义域为                            （   ）

阅读短文，选择正确的答案。
    A little mouse thought he was the tallest and strongest animal in the world. His mother said to him, "Don't say that in front of an elephant. He doesn't like that." The little mouse didn't listen to his mother. He went out to look for the elephant, but he didn't know who the elephant was. He asked an ant(蚂蚁) first, "Are you an elephant?" "No, I'm not," said the ant. "An elephant is much bigger than I am." Suddenly(突然), he saw four big trees. "Let me climb up(爬上) a tree. Then I can see where the elephant is," said the little mouse. "Get down! Get down!" someone shouted(喊) to him. "I'm the elephant. Go and climb that tall tree nearby. Then you can see me." "Now, I see. The elephant is the tallest and strongest animal in the world," said the little mouse.

You look really cool in the new dress, dear. How much did you ________ it?

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Something _______ wrong with the machine, and it _______ not work.