为什么会下雨WhyDoesItRain _这世界为什么总有雨呢英文

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又到梅雨季节，最近天天下雨，天气已经很久没有放晴了，那么为什么会下雨呢？雨水是如何形成的呢？
Plants need it to grow, animals need it to survive, and the human body needs it to stay hydrated and keep functioning.
植物靠它生长，动物赖以生存，人体需要它来保持水分，维持机体正常运作。
Water is an essential building block to life and it comes to us from above.
水是生命的基本组成部分，它从天而降。
Rainwater fills streams, rivers, and lakes.
雨水注满了小溪、河流和湖泊。
It carries with it the potential for life to flourish.
承载着让生命蓬勃发展的潜力。
It can turn an arid desert in to an oasis; convert a stream to white water rapids in the monsoon season, and breathe life into the harshest places on earth.
它能把干旱的沙漠变成绿洲；在雨季把浅溪变成急流，给地球上最严酷的环境带来生命。
So how do clouds form to keep giving us the essential H2O we need?
那么，云是如何形成并持续提供我们所需的水的呢？
That's what we'll find out today, in this episode of The Infographics Show: Why Does It Rain?
这是我们在今天的“信息图表秀”要研究的：为什么会下雨？
Clouds are possibly the most interesting and beautiful of all weather phenomena.
云可能是我们见到的最有趣、最美丽的天气现象了。
They form in a wide variety of shapes and sizes, but are all made of the same thing. . . water.
它们大小不一，形态各异，但都由水而来。
Though we may not notice it, almost all the air around us is moist because it contains water in the form of vapor.
虽然我们可能注意不到，我们周边的空气几乎都是潮湿的，因为空气里有水分并以水蒸气的形式存在着。
You can't see the water vapor, because it's a gas, but it is still there.
由于水蒸气是气态的，所以我们看不到它，但它依然真实存在。
Water can be either solid as ice, liquid as water, or gas, which is a vapor.
水能以固态存在，比如冰；能以液态存在，比如水；或以气态存在，那就是水蒸气。
Vapor has no smell and it's invisible.
水蒸气无色无味。
But you can feel it.
但我们仍然能感觉到它。
Imagine a hot and sticky day in summer, or a cold foggy day in winter.
试想炎炎夏日里粘粘的空气，亦或是寒冬里的冷气。
Those sensations are water vapor.
我们感觉到的这些都是水蒸气。
If you put steam or vapor under the microscope, you would see millions of tiny water droplets floating in the air.
如果在显微镜下观察水蒸气，我们能看到数以百万计的小水滴漂浮在空气里。
This is the same process that forms clouds - millions of tiny water droplets condensing out of the air to form liquid water.
这和云彩的形成过程相同-空气中数以百万计的水滴遇冷凝结成液态水。
But why does water condense out of air and become visible as a cloud?
那为什么水能从空气中凝结而成为可见的云呢？
Warm air holds water vapor better than cool air, so when warm air starts to cool, it can no longer hold as much of the vapor.
暖空气中的水蒸气比冷空气中的更多，所以当暖空气的温度降低时，就存不住那么多的水蒸气了。
The extra water vapor has to go somewhere.
多余的水分不得不去到别处。
It condenses out as water.
所以就凝结成了水。
To see this in action, go outside and stare up at a cloud.
要想看到这个变化，就要去外边盯住一朵云观察。