题干

骑自行车的运动是一项很好的锻炼方式,不限时间,不限速度。它不再只是一种代步工具,更是愉悦心灵的体育运动。骑自行车运动是需要大量氧气的运动,使肺通气量增大,肺活量增加,肺的呼吸功能提高,还可以强化心脏功能。图乙是研究获得骑行速度与摄氧量的关系图。由图可知:随着骑行速度的增加,人体的摄氧量不断增加。请利用所学的知识分析摄氧量为什么会随着骑行速度的增加而增加?

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答案(点此获取答案解析)

骑行速度的增加,自行车的动能也就增加,而自行车的动能是由人体的化学能转化而来,因此人体消耗的化学能也就增加。而人体通过呼吸作用释放出有机物中的化学能,这也势必需要增强呼吸作用,呼吸作用需要消耗氧气,因此摄氧量也就增加。

同类题3


Spring is coming . The flowers will start blossoming (开花)and the trees will be filled with colors. It’s time of the year for people to plant trees. Planting trees is a good way to protect our environment. But most of us don’t have a place to plant trees. So what can we do for protecting the environment? We can make a difference from the others. For example, we can think about a way to make people cut down fewer trees. As we know, paper is made from trees. If we use less paper, we can save a lot of trees. Then we may have a problem that how to use less paper. Let me tell you my ideas.                                                   
Reducing Our Paper Waste
Every day we just use the paper and we don’t think about where the paper comes from.Let us think about wasting a piece of paper is like wasting a tree. We can start with reducing the amount of paper products that we use. This could be done by such a simple way as using e-mail instead of writing notes.
Reusing

We could reuse paper that is clean on one side for drafts, notes and even photocopies. As students, we could reuse paper by doing our research online or at libraries rather than buying lots of written paper. Sharing books or buying a used textbook for school is another way of reusing.
Recycle
We should consider recycling notebook paper, newspapers, magazines and colored paper. We can buy paper towels, tissues, and toilet paper that have been made from recycled paper. Don’t throw away the wasted newspapers or books which are not useful to you.
       

 

同类题4

阅读《散步》相关语段,回答问题。

    ①我们在田野上散步:我,我的母亲,我的妻子和儿子。

    ②母亲本不愿出来的;她老了,身体不好,走远一点就觉得很累。我说,正因为如此,才应该多走走。母亲信服地点点头,便去拿外套。她现在很听我的话,就像我小时候很听她的话一样。

    ③天气很好。今年的春天来得太迟,太迟了,有一些老人挺不住,在清明将到的时候死去了。但是春天总算来了。我的母亲又熬过了一个严冬。

    ④这南方初春的田野!大块儿小块儿的新绿随意地铺着,有的浓,有的淡;树枝上的嫩芽儿也密了;田里的冬水也咕咕地起着水泡儿……这一切都使人想着一样东西——生命。

    ⑤我和母亲走在前面,我的妻子和儿子走在后面。小家伙突然叫起来:“前面也是妈妈和儿子,后面也是妈妈和儿子!”我们都笑了。

    ⑥后来发生了分歧:母亲要走大路,大路平顺;我的儿子要走小路,小路有意思。不过,一切都取决于我。我的母亲老了,她早已习惯听从她强壮的儿子;我的儿子还小,他还习惯听从他高大的父亲;妻子呢,在外面,她总是听我的。一霎时,我感到了责任的重大,就像民族领袖在严重关头时那样。我想找一个两全的办法,找不出;我想拆散一家人,分成两路,各得其所,终不愿意。我决定委屈儿子,因为我伴同他的时日还长。我说:“走大路。”

    ⑦但是母亲摸摸孙儿的小脑瓜,变了主意:“还是走小路吧。”她的眼随小路望去:那里有金色的菜花,两行整齐的桑树,尽头一口水波粼粼的鱼塘。“我走不过去的地方,你就背着我。”母亲对我说。

    ⑧这样,我们在阳光下,向着那菜花、桑树和鱼塘走去。到了一处,我蹲下来,背起了母亲,妻子也蹲下来,背起了儿子。我的母亲虽然高大,然而很瘦,自然不算重;儿子虽然很胖,毕竟幼小,自然也轻;但我和妻子都是慢慢地,稳稳地,走得很仔细,好像我背上的同她背上的加起来,就是整个世界。