题干

下列事实说明空气中含有哪些成分?(填物质名称或符号都对)

(1)小白鼠在装有空气的密闭容器中可存活一段时间,说明空气中含有 ____

(2)空气是制造氮肥的主要原料说明空气中含有 ____

(3)酥脆的饼干在空气中放置会逐渐变软说明空气中含有 ____

(4)长期放置在空气中的石灰水表面有一层白色物质说明空气中含有 ____

上一题 下一题 0.0难度 选择题 更新时间:2019-11-28 12:02:35

答案(点此获取答案解析)

氧气或O2,氮气或N2,水或H2O,二氧化碳或CO2

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    If you think about school, is there one teacher who stands out above all others? One person who is your favorite and who really inspires you? Why?____ I've decided that I want to become a teacher because teaching is so rewarding and it provides so many opportunities. I get to inspire future generations – what could be better?

    I'm currently helping out in two schools – a primary and a secondary school – and I'm actually really enjoying it. Some says are challenging and I ask myself why I am doing it, but then one of my students will answer a question or be interested in my lesson and suddenly everything becomes worthwhile.____

    I plan my own lessons and make them as fun as serious as I like.____ That is why my lessons are never boring. Sometimes my classes don't go according to the plan, so I switch the way I teach and do something that I know my students will enjoy.

    ____ I teach biology, geography, history, technology, social sciences and music … all is English! I get to study English literature, which is my passion, and pass on my knowledge and enthusiasm to my students, and I get to teach a huge variety of classes and age groups.

    ____ As a result, I have to try and cater for everybody by including a variety of tasks and exercises as well as interesting multimedia, like videos and games.

The best classes are when I give the students a topic to discuss – usually one which they feel very passionate about – and let them have their say.

A. Teaching is so exciting.

B. I create lesson plans to suit each of the ages.

C. I realize I am great to help someone to learn.

D. I've found that each student learns differently.

E. I've been thinking these questions over recently.

F. I'm excited to get started on my teacher training.

G. I also love the fact that I teach English in everything.