The moon looks bigger than the stars at night. But in fact, it is smaller than any of them. The moon looks big to us, because it is closer to us than any star. The moon goes around the earth. It makes one trip about four weeks. The moon is a round ball and looks beautiful. Don't you think so? Now people know quite a lot about the moon. There is no air or water on the moon so there are not any trees or animals, or people on the moon. The moon gets its light from the sun, but some places on the moon are quite dark. Then days on the moon get hotter than boiling  water. The nights get colder than the North Pole  on the earth. The moon makes one trip round the earth in about   _  .
a week four weeks a year 24 hours