题干

实验中的变量有自变量、因变量和无关变量.下列相关变量的处理或分析错误的是(    )

选项

实验名称

处理

分析

探究唾液淀粉酶最适温度

将唾液和淀粉液混合后,将每一组温度控制在37℃

控制无关变量

探究植物生长调节剂对扦插枝条生根的作用

比较各组插条生根的长度

检验因变量

探究酵母菌的呼吸方式

一组密封,一组通入空气

控制自变量

探究影响人工生态瓶稳定的因素

生态瓶应放在阳光下直接照射

控制因变量

A:①②

B:①④

C:②③

D:②④

上一题 下一题 0.0难度 选择题 更新时间:2018-09-18 11:01:58

答案(点此获取答案解析)

B

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    I could feel the judging eyes of my family burning a hole into the back of my head as I picked up my phone. All of a sudden, the chattering in the living room died and all I could hear was the sound of the turkey sizzling (发出嘶嘶声) in the oven.

    “Look at her! She's been on her phone all day long! It's all your fault! Children will never respect elders if they are not taught how to behave! ” my grandmother shouted.

    I was very shocked and angry! I opened my mouth to say something, but words failed me and I just sat down quietly on the chair like a mouse in its trap. I thought “Here we go again.” I truly love my family and I would do anything for them. I also know that they would do anything for me as well. However, there are moments that make me feel that they are just stuck with me. They all agree on one thing: technology is wrecking me.

    If I am going to be treated like a child or completely ignored, I will most likely not enjoy your company, and I feel that this applies to (适用于) the majority of the people. So I sometimes simply shut myself in my room and listened to the voices coming from the living room, thinking: They all grew up in a world so different that it amazes me how they have actually gotten this far. They did not have phones or any type of advanced technology, which is both good and bad. Bad because they had almost no type of fast communication, and good because they were forced to interact (互动) with one another, which is something today's society is lacking in. However, maybe if they made an effort to be aware of how things work nowadays, they would not be so against everything.