Teacher Li, when it rains, is the sky crying?

No, rain is when water vapor turns into water droplets and falls down.

What is water vapor?

Water vapor is water that turns into warm gas, rises into the air, and cannot be seen.

How does it turn into rain?

When water vapor meets cold air, it turns into tiny droplets. When many droplets gather together, they form clouds.

When there are many droplets in the cloud, they fall down, right?

Yes! When the droplets become heavy, they fall from the clouds and become rain.

I see! Rain is water returning to the ground.

That's right, water keeps circulating between the sky and the ground. This is called the water cycle.