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  • 水 - 高级水

    Water - Iguassu Waterfall

    Does dihydrogen oxide ,  or dihydrogen monoxide, sound dangerous?
    ::二氧化氢或一氧化二氢是否听起来很危险?

    Another name for this compound is water. Water can create some absolutely beautiful sights. Iguassu Falls is the largest series of waterfalls on the planet, located in Brazil, Argentina, and Paraguay. And water is necessary for life. Water, like carbon, has a special role in biology because of its importance to organisms . Water is essential to all known forms of life. Water, H 2 O, is such a simple molecule, yet it is this simplicity that gives water its unique properties and explains why water is so vital for life. 
    ::这个化合物的另一个名称是水。水可以创造一些绝对美丽的景象。 Iguassu Falls是地球上最大的一系列瀑布,位于巴西、阿根廷和巴拉圭。水是生命所必需的。水与碳一样,在生物学中发挥着特殊的作用,因为它对生物非常重要。水对所有已知的生命形式都至关重要。水,H2O,是一个简单的分子,但水的特性正是如此简单,它赋予了水独特的特性,解释了为什么水对生命如此重要。

    Water is a common chemical substance on Earth. The term water generally refers to its liquid state. Water is a liquid over a wide range of standard temperatures and pressures. However, water can also occur as a solid (ice) or gas (water vapor).
    ::水是地球上常见的化学物质,水一词一般指其液体状态,水是各种标准温度和压力的液体,但水也可以作为固体(冰)或气体(水蒸气)出现。

    Where Is All the Water?
    ::水都到哪儿去了? 水都到哪儿去了?

    Of all the water on Earth, about two percent is stored underground in spaces between rocks. A fraction of a percent exists in the air as water vapor, clouds, or precipitation . Another fraction of a percent occurs in the bodies of plants and . So where is most of Earth’s water? It’s on the surface of the planet. In fact, water covers about 70 percent of Earth’s surface. Of water on Earth’s surface, 97 percent is salt water, mainly in the ocean. Only 3 percent is fresh water . Most of the freshwater is frozen in glaciers and polar ice caps. The remaining freshwater occurs in rivers, lakes, and other freshwater features.
    ::在地球上的所有水中,大约2%被存放在地下的岩石间空间中。空气中有一小部分是水蒸气、云层或降水的。另一部分是植物和水体中的部分。因此,地球上的大部分水在哪里?在地球表面?事实上,水覆盖了地球表面的大约70%。在地球表面的水中,97%是盐水,主要是海洋中的盐水。只有3%是淡水。淡水大部分冻结在冰川和极地冰盖中。剩下的淡水出现在河流、湖泊和其他淡水特征中。

    lesson content
    Most of the water on Earth consists of saltwater in the oceans. What percent of Earth’s water is fresh water? Where is most of the freshwater found?

    Although clean fresh water is essential to human life, in many parts of the world it is in short supply. The amount of fresh water is not the issue. There is plenty of fresh water to go around because water constantly recycles on Earth. However, fresh water is not necessarily located where it is needed, and clean fresh water is not always available.
    ::尽管清洁淡水对人类生活至关重要,但在世界上许多地方却缺水,淡水量不是问题所在,因为地球上的水不断回收,因此有大量淡水可以流传,然而,淡水不一定是需要的地方,清洁淡水并非总能得到。

    How Water Recycles
    ::水循环利用方式

    Like other matter on Earth, water is continuously recycled. Individual water molecules are always going through the , in which molecules of water cycle through both the living and non-living parts of the (discussed in the Recycling Matter: The Water Cycle (Advanced) concept). In fact, water molecules on Earth have been moving through the water cycle for billions of years. In this cycle, water evaporates from the Earth’s surface (or escapes from the surface in other ways), forms clouds, and falls back to the surface as precipitation. This cycle keeps repeating. Several processes change water from one state to another during the water cycle. They include:
    ::与地球上的其他物质一样,水也在不断循环。 单个水分子总是通过水循环分子通过水的活体部分和非活体部分(在再循环物质中讨论:水循环(高级)概念 ) 。 事实上,地球上的水分子已经通过水循环数十亿年了。 在这一循环中,水从地球表面蒸发(或以其他方式从地表渗出 ) , 形成云层,并随着降水而回落到地表。 这一循环不断重复。 在水循环中,若干过程将水从一个州转移到另一个州。 这些过程包括:

    • Evaporation —Liquid water on Earth’s surface changes into water vapor in the atmosphere .
      ::蒸发 -- -- 地球表面的贫化水变成大气中的水蒸气。
    • Sublimation —Snow or ice on Earth’s surface changes directly into water vapor in the atmosphere.
      ::升华——地面上的雪或冰直接变成大气中的水蒸气。
    • Transpiration —Plants give off liquid water, most of which evaporates into the atmosphere.
      ::Transship-Plants释放出液态水,其中多数蒸发到大气中。
    • Condensation —Water vapor in the atmosphere changes to liquid water droplets, forming clouds or fog.
      ::浓缩-大气中的水蒸气改变为液态水滴,形成云或雾。
    • Precipitation —Water droplets in clouds are pulled to the Earth’s surface by gravity, forming rain, snow, or another type of falling moisture.
      ::降水——云中的水滴通过引力被拉入地球表面,形成雨水、雪或其他类型的水分下降。
    lesson content
    Like other biogeochemical cycles, there is no beginning or end to the water cycle. It just keeps repeating.

    Summary
    ::摘要

    • Most of Earth’s water is salt water located on the planet’s surface.
      ::地球的水大部分是位于地球表面的盐水。
    • Water is constantly recycled through the water cycle, cycling through both the living and non-living parts of the biosphere.
      ::水不断通过水循环循环循环循环循环,循环循环,通过生物圈的生物部分和非生物部分循环循环。

    Review
    ::回顾

    1. Where is most of Earth’s water? What percent of that is salt water?
      ::地球的水大部分在哪里?其中有多少是盐水?
    2. Where is most of the fresh water on Earth?
      ::地球上大部分淡水在哪里?
    3. What are the two concerns of fresh water?
      ::淡水的两个关切是什么?
    4. What is the water cycle?
      ::什么是水循环?
    5. Draw a circle diagram to represent the basic components of the water cycle. Identify the states of water and the processes in which water changes state throughout the cycle.
      ::绘制圆形图以代表水循环的基本组成部分。 确定水的状态和水的变化在整个循环中状态的过程 。