After it rains, sometimes we can see a beautiful rainbow in the sky.
雨后，有时候我们会在天空中看到美丽的彩虹。
Rainbows appear when sunlight passes through tiny water droplets in the air.
当阳光透过空气中的小水滴时，就会形成彩虹。
The water droplets act like tiny prisms.
水滴就像小小的棱镜。
When light enters a water droplet, it bends.
当光进入水滴时，会发生弯曲。
This bending of light is called refraction.
这种光的弯曲现象叫做折射。
Inside the droplet, the light reflects and spreads into different colors.
在水滴内部，光被反射并分散成不同的颜色。
This process creates a rainbow.
这个过程形成了彩虹。
A rainbow has seven colors.
彩虹有七种颜色。
The colors are red, orange, yellow, green, blue, indigo, and violet.
它们依次是红、橙、黄、绿、蓝、靛、紫。
Red is on the outer edge, and violet is on the inner edge.
红色在彩虹的外侧，紫色在彩虹的内侧。
Rainbows always appear opposite to the sun.
彩虹总是出现在太阳的对面。
You need both sunlight and water droplets to see a rainbow.
要看到彩虹，需要阳光和水滴。
That’s why rainbows often appear after rain when the sun comes out.
这就是为什么彩虹常常出现在雨后太阳出来的时候。
Sometimes, you can see a double rainbow.
有时候，你还能看到双彩虹。
The second rainbow is fainter and has reversed colors.
第二道彩虹较淡，而且颜色顺序相反。
You can also see rainbows near waterfalls and fountains.
在瀑布或喷泉附近，你也可以看到彩虹。
People love rainbows because they are rare and beautiful.
人们喜欢彩虹，因为它们既罕见又美丽。
Now you know that rainbows appear after rain because sunlight is refracted through water droplets!
现在你知道彩虹是因为阳光经过水滴折射而形成的了！
