已知全集I=R，若函数f（x）=x2-3x+2，集合M={x|f（x）≤0}，N_爱下问搜题

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问题填空题

已知全集I=R，若函数f（x）=x²-3x+2，集合M={x|f（x）≤0}，N={x|f′（x）＜0}，则M∩∁_IN=______．

答案

由x²-3x+2≤0，解得1≤x≤2，∴M={x|1≤x≤2}．

f′（x）=2x-3＜0，解得x＜

3

2

．

∴N={x|x＜

3

2

}，

∴C_lN={x|x≥

3

2

}．

∴M∩∁_IN={x|

3

2

≤x≤2}．

故答案为{x|

3

2

≤x≤2}．

补全对话，情景问答

根据对话内容，从方框内选择恰当的句子并将其字母代号填入对话相应的空白处，使对话完整，
合乎情景（有两个多余选项）。

A. Are you sure?
B. Because I like talking to people.
C. Why do you want to do that?
D. I want to be a driver.
E. Why do you want to be an actor?
F. I think I want to be a reporter.
G. What do you want to be when you are older?

Kelly: So, Cathy, tell me, what do you want to be when you are older?
Cathy: (1)________
Kelly: A reporter? Why do you want to do that?
Cathy: (2)________ What about you, Kelly? What do you want to be?
Kelly: I want to be an actor.
Cathy: (3)________
Kelly: Because I like to sing and dance.
Cathy: And you, Nancy? (4)________
Nancy: I want to be a teacher.
Cathy: A teacher? (5)________
Nancy: Yes, I am. I want to be a teacher because I love school.

填空题

冷裂纹是在较低的温度下产生的（）开裂。