Rainbows

Rainbows written by Sean McCollum. Focus question. How does a rainbow form?

《彩虹》，作者：肖恩·麦科勒姆。 核心问题 彩虹是怎么形成的？

Introduction. When the sun comes out after it rains, run outside. You may see a rainbow in the sky.

引言： 雨后太阳出来的时候，快跑到外面去吧， 你说不定能在天空中看到彩虹。

Rainbows are tricks made by light. We can see them, but we can't touch them or walk around them. They seem to move away when we try to get close to them. Science can explain how rainbows happen.

彩虹是光变的小魔术哦。 我们能看见它们，却摸不到，也没法走到它们旁边。 当我们试着靠近彩虹的时候，它们好像会跑远。 科学可以解释彩虹是怎么出现的。

where and when rainbows appear. Look around the next time you see a rainbow. The sun will be shining from behind you. There will be rain in front of you where you'll see the rainbow.

彩虹出现的时间和地点 下次你看到彩虹的时候，看看周围哦。 太阳会在你的身后照耀。 你的前方会有雨。你就是在那里看到彩虹的。

Rainbows need water drops and sunlight to form. They can even form under a bright moon. These are called moonbows.

彩虹的形成需要小水滴和阳光。 它们甚至能在明亮的月光下形成哦。 这种彩虹叫做月虹。

We usually see a rainbow as a half circle. It actually forms a full circle. From the ground, we can only see the top half.

我们通常看到的彩虹是半圆形的。 其实它的完整形状是圆形的哦。 站在地面上，我们只能看到上半部分。