在经济学中,空气是不是属于免费物品?
在经济学中,空气属于免费物品。商品的属性有两个条件:1.要有人参与劳动;2.有使用价值。而空气虽然有使用价值,却并没有劳动价值,所以不是商品,是免费物品。
求一个空气动力学模拟软件,有免费的没有啊?
fluent或者star-cd 网上都有的,但是因为都是破解的,所以难免用的时候出现一些bug,或者某些模块功能丧失 不过做一般的工作都可以了,有些设计公司也没有用正版的,因为买...
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享受空气和阳光的句子?
享受阳光,享受新鲜空气,不懂得享受,就不懂得生活。在一个阳光明媚的夏日,空气中弥散着一种懒惰而安详的气息,阳光让我睁不开眼睛。晒着免费的太阳,呼吸着免费的空气,时间很慢,阳光很暖...
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阅读空气那款游戏怎么玩
(仅供参考……)1、地铁(一:二人组):红色压对象:人。操作:向左移动际。在地铁中在你面前出现二人组,此时你应该让出空位给他们。做一个真正的绅士。2、填坑:红色对象:人。操作:向...
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阅读乐园风的形成 1根据短文内容填空 对流就是空气受热()补充()受
经初三了,马上中考了,你就少玩一会儿吧!等考普及面犯最与上好的大学有了好的工作,你再玩也不迟啊!”这是母亲经常念在嘴边的。那么试问,考完大学是不是还要继续努力学习找个好工作呢?找...
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(3分)阅读以下有关“空气成分”的卡通图,**:
试题答案:21% 氮气 0.03%
阅读以下有关“空气成分”的卡通图,**:我能使澄清的______变浑浊.
360问答试题答案:二氧化碳能穿木深复战夜许介纪职使澄清石灰水变浑浊,空气按体积分数计算,氮气占78%、氧气占21%、二氧化碳占0.03%.故答案为:石灰水;21%,氮气,0.0...
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(3分)阅读以下有关“空气成分”的卡通图,**:
21%氮气0.03%空气按体积分数计算,氮气占78%、氧气占21%、二氧化碳占0.03%.
阅读以下有关“空气成分”卡通图,填空并把你从图中获得的信息填在横线上1. 填写下列序号中的结染论: a ...
1.a氧气;b78%;c0.03%。2.(1)空气是混合物;(2)空气主要成分是氮气和氧气。(其他合理答案也得分)(1)空气中氮气的体积分数为21%,氧气的体积分数为78%,二氧...
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阅读以下有关“空气成分”的卡通图,**:我能使澄清的______变浑浊.
二氧化碳能使澄清石灰水变浑浊,空气按体积分数计算,氮气占78%、氧气占21%、二氧化碳占0.03%.故答案为:石灰水;21%,氮气,0.03%.
阅读以下有关“空气成分”卡通图,**并把你从图中获得的信息填在横线上(1)填写图中a、b、c代表的成分名称或数据:a______;b______;c______.(2)你得到的信息是(任意写出两条):①______;②______.(3)根据空气成分,用化学符号**:①小白鼠在装有空气的密闭容器中可
试题答案:(1)由图示及课本来自中所学知识可知道:按体积分数计算氮气占78%,氧气占21%,稀有气体占0.94%,二氧化碳占0.03%,其360问答他气体和杂质占0.03%.(2...
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阅读弗雷德·皮尔斯的《空气中取水》一文,完成问题。 ①任何时候,大气中都含有105亿英亩呎 ① 水敌息助变般统,
1.不能去掉。“据说”一词表明“喊得越响,雨下得越大”的情形并不确定;如果去掉,说法就显得绝对,与事实不符,体现了说明文语言的准确性。2.运用列数字、作比较的方法,具体形象地突出...
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空气在哪既厚社时大混范无雨优里短文二年级阅读
空气在哪里》是一篇童话故事。通过写小猴子和空气玩捉迷藏的游戏,介绍了空气的作用及特点。教学这篇课文时,我注意培养学生自学生字的能力。我让学生在自读课文时圈画出生字,多读几遍,在小...
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