题干

为了区别开空气、氮气、氧气、氢气和二氧化碳五瓶无色气体,小华同学设计了如下实验方案,请你填写出完整的实验报告.

 实验步骤

 实验现象

 实验结论

 1.将燃着的木条分别伸入瓶内

 A瓶:木条燃烧状况没有明显变化

该瓶气体是空气

 B瓶:____.

该瓶气体是氧气

C瓶:____.

该瓶气体是氢气

D瓶和E瓶;燃着的木条都____

两气体是氮气和二氧化碳

 2.____

D瓶:____

D瓶气体是氮气

E瓶:____

E瓶气体是二氧化碳

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答案(点此获取答案解析)

\u6728\u6761\u71c3\u70e7\u7684\u66f4\u65fa,\u6c14\u4f53\u80fd\u71c3\u70e7,\u7184\u706d,\u5f80D\u3001E\u4e24\u74f6\u4e2d\u5206\u522b\u5012\u5165\u6f84\u6e05\u77f3\u7070\u6c34\uff0c\u5e76\u632f\u8361,\u65e0\u660e\u663e\u73b0\u8c61,\u6f84\u6e05\u

同类题3

阅读表达 阅读下面的短文并用英语回答问题,并将答案写在答题卡上标有题号的横线上。

    The way we spend our time can be. divided into three groups,or jars(罐子).These would be the necessary tasks jar, the voluntary tasks jar and the happiness jar.

    Every day,we spend time filling the necessary tasks jar. We fill this jar with useful things,like making money,doing housework,buying food and paying bills. We then fill another jar with voluntary tasks like taking children to activities and cooking family meals. Those jars are very important,but we may not enjoy them. If we don't fill them each day,our family won't run properly.

    However, we often forget to fill the third jar—the happiness jar. This is the jar that we fill with activities that make us happy. Is your happiness jar sometimes empty at the end of the day? We all have days like that. Between doing all the necessary, and voluntary tasks,time flies by on some days,and before we know it,it is time for bed.

    That is why each day we try to fill our happiness jar. Most days,I fill mine by going to the ballroom dance(社交舞)class. Playing music is another way that I fill my happiness jar. This week,I was happy to take part in an orchestra(管弦乐队)practice at my church(教堂).At the end of the evening, my happiness jar was full.

    Consider how your time is spent. Try to find ways to achieve a balance. At the end of the day,hopefully we've done all we can to make sure that our happiness jar is filled.