After many rainy and gloomy days, the sun appeared in the sky and lit up the earth. Alexis and Alice thought about how important it is for people. If there were no sun, there would be no trees, flowers, or our beloved dogs. In general, life on our planet is due to the presence of the sun. The two children have many questions about our solar system, about the earth and the sky, about the universe. What they definitely know is that they always need to wear sunglasses!