21 Gases Matter

Gases Matter by ANNA PROKOS With the Editors of TIME FOR KIDS

安娜·普罗科斯与《儿童时代》编辑合作

CHAPTER 1 What Is Matter? Think about all the things on Earth. Everything that takes up space is called matter. Houses, toys, roads, lakes, plants, and animals are all made of matter. You are made of matter. The air you breathe is made of matter, too. There are three kinds of matter. Solids have their own shape. Liquids take the shape of what they are poured into. Gases have no shape. Sometimes you cannot see them. Air is made of gases. This book is about gases.

第一章物质是什么?想想地球上的所有事物。 任何占据空间的东西都叫物质。 房子、玩具、道路、湖泊、植物和动物都是由物质构成的。 你是由物质构成的。你呼吸的空气也是由物质构成的。 物质有三种。 固体有自己的形状。 液体的形状取决于它被倒入的东西。 气体没有形状。有时你看不见它们。 空气是由气体构成的。这本书是关于气体的。

CHAPTER 2 Every Breath You Take Take a deep breath. You are now full of gas! Yet you cannot see it, taste it, or smell it. Air is made of gases. Gases are important for life on Earth. The deep breath you took is full of oxygen. Plants and animals need oxygen to live. Earth is the only planet that has enough oxygen for all living things. Oxygen is in air and water. But it is not the only gas we need.

第2章你的每一次呼吸深呼吸。 你现在充满了汽油!但是你看不见它，尝不到它，也闻不到它。 空气是由气体构成的。气体对地球上的生命很重要。 你深深吸了一口气，里面充满了氧气。 动植物需要氧气才能生存。 地球是唯一一个有足够氧气供所有生物生存的星球。 氧气存在于空气和水中。 但它并不是我们唯一需要的气体。

CHAPTER 3 Blown Away The air you breathe out is different from the air you breathe in. The air that comes out is a mix of oxygen and carbon. Together, carbon and oxygen make a gas called carbon dioxide. Plants need carbon dioxide to make food. Plants give off oxygen into the air. It is the oxygen that humans— and all animals— breathe in. Plants and animals work together to make the gases they need.

你呼出的空气和吸入的空气是不一样的。 排出的空气是氧和碳的混合物。 碳和氧合在一起形成一种叫做二氧化碳的气体。 植物需要二氧化碳来制造食物。 植物向空气中释放氧气。 它是人类和所有动物呼吸的氧气。 植物和动物一起工作来制造它们所需要的气体。

CHAPTER 4 From Soil to Air, and Back Again Most of our air is made of a gas called nitrogen. Plants, people, and animals need nitrogen in order to live. But they cannot get it from the air. They must get nitrogen from the soil. The roots of plants take in nitrogen from the soil. When plants die, they become part of the soil. The nitrogen goes back to the soil, too.

从土壤到空气，再从土壤到空气，我们的大部分空气都是由一种叫做氮气的气体构成的。 植物、人类和动物都需要氮来生存。 但他们不能从空气中获得。 他们必须从土壤中获取氮。 植物的根从土壤中吸收氮。 当植物死亡时，它们成为土壤的一部分。 氮也会回到土壤中。