题干

下列有关实验现象或事实叙述错误的是(   )

A:切完西瓜的菜刀洗净擦干放在通风干燥处可以防止生锈

B:铁丝在氧气中燃烧,火星四射,生成黑色固体

C:用青铜片(铜锡合金)和铜片相互刻画,青铜片留有划痕

D:将二氧化碳慢慢倒入放有两支高低蜡烛的烧杯中,燃着的蜡烛自下到上依次熄灭

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答案(点此获取答案解析)

C

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    Before I had my son, I spent two years working with children with disabilities. I learnt that shouting and threats of punishment would result in a disaster. Coming up against their behaviour could only make the job harder and their behaviour more extreme. I found something that worked, though.

    There was a very naughty boy in the nursery and a teacher who was generally very confident with the children was asked to take charge of him. One day the boy joined a session in the room next to mine. His appearance created an atmosphere of tension. He spent the entire session running around, hitting and kicking, and destroying property.

    I was in the craft room working with some other children when my co­worker told me that this boy's teacher was in tears, and could not get control of the situation. As we were talking, the boy ran in. I told my co­worker that I would take care of him.

    I closed the door. He was full of energy, throwing things around and making a huge mess. But I could see that he was doing all these to annoy me. He needed connection, and this was the only way he knew how to ask for it. So I sat back down and kept quiet. Then he slowed down and began making a rocket. I talked to him about it. We continued like this for a few minutes before I slipped into the conversation:

    “So what happened today?”

    It was purely a question, no blame or anger in my tone. I believe that if I had criticized him, the gate that was slowly opening would have shut firmly closed. He told me that the teacher didn't let him do what he knew well due to safety but asked him to do what he disliked. He also admitted that he had enjoyed making her run around and saw it as a game. I explained that his teacher had not seen it as a game and was very upset. This again was stated simply as a fact. I suggested that next time he had a session, he talk about what he hoped to do at the start, which might be easier for everyone. He agreed and was quiet for a moment. Then he looked at me with tears in his eyes before quietly asking if he could go to find his teacher to apologize.