We know much about the universe(宇宙). It means the earth, the sun, the moon and the stars and the spaces between them.
Most of the stars are bigger than the moon, but they look much . Because they are far from the earth. At night, the moon is high in the sky like a light. But the moon has no light of own. The light of the moon comes from the sun. The sun gives us light, heat and life. And the plants, animals and men will die the sun.
The earth is going round itself all the time. the part of the earth turns to the sun, it is day. The opposite part of the earth is night.
The earth is our homeland. We should love it.
