1．若集合$A=\left\{i.i^2.i^3.i^4\right\}$ （$i$ 是虚数单位），$B=\left\{1.-1\right\}$ ，则$A\cap B$ 等于 (     )

我们班的语文老师幽默风趣、平易近人，数学老师教学严谨、不苟言笑，历史老师知识渊博、见解独到……面对这些风格不同的老师，我们应该（    ）

①承认老师之间的差异，接纳每位老师的“不同”    ②尊重老师的“不同”，更深入地了解老师

③善于发现不同风格老师的优点                               ④主动和不同风格的老师交往

如图所示为农业生态系统模式图．请据图回答：

函数f（x）=ax²+bx+c（a＞0）对于任意的x∈R有f（1﹣x）=f（1+x），则f（2^x）与f（3^x）的大小关系是（　　）

补全对话。其中有一个多余选项。

A: Hi, Molly. Where's your brother Larry? I thought he was joining us.

B: Hi, Kathy. I'm sorry. ____ He is working late tonight.

A: Oh, Larry's working late again?

B: Yeah, he is.

A: I see……I really don't think sixteen-year-olds should be allowed to work at night. ____

B: Oh, I disagree with you. Teenage boys never get tired.

A: Well, maybe. ____

B: That's true. He needs time to do homework.

A: And you know, Molly……he should really cut his hair.

B: Oh, I don't know. ____

A: Yes, I do. It doesn't look clean. And I think he should stop wearing that silly earring.

B: Hmm……I disagree. I kind of like it. It looks cool!

A: You know another thing that worries me? ____

B: Yeah, I know. I think he shouldn't work on weekends

A: That's right. He needs to spend time with friends.