The moon looks     1     than the stars at night.     2     in fact, it is smaller than any other stars. The moon looks big to us, because it is closer     3     us than any stars. The moon goes around the earth. It makes one trip about four weeks. The moon is a round ball and looks beautiful.

Now people know quite a lot about the moon. There is no air or water on the moon, so there are not     4     trees or animals, or people on it. The moon gets its light (光) from the sun, but some places on the moon are quite dark. It’s very hot on the moon during the day, but it’s very cold at     5    .

The moon     1     around the earth. It is quite near to us in     2    . It is only 380,000 kilometres away and man has     3     visited it. So far, no man has travelled     4     than the moon, but spaceships without people have     5     other planets of the universe.

Many countries have     6     up satellites(卫星) into space.

These satellites go     7     the earth and help us to learn more about the earth, the weather and other things. Many countries use these satellites to send and receive     8    . For example,     9     their help, China can send its TV and radio programmes to other countries. We can also use satellites to     10     us make telephone calls to foreign countries.

The moon is our space neighbour. It is a ball of     1     that goes around our home, the Earth. It takes the moon 27 days and eight hours to go around Earth one time. The same side of the moon ways     2     Earth.

The moon is very different from Earth. There is no air, water,     3     wind on the moon. If you visited the moon, you would have to wear a special suit to help you breathe. You would also     4     less on the moon and be able to jump six times higher!

The moon has     5     and dark spots. The bright spots are hills and mountains. The dark spots are places where flying rocks have hit the moon. There are also many flat parts of the moon. These parts look     6     our seas, but you would not be able to sail in the seas of the moon! Do you know why?

The earth is a planet and it     1     around the sun. Seven other planets also go around the sun.    2    of them has an environment like     3     of the earth, so scientists do not think they will find life on them. The sun and its planets are     4     the solar system, and our solar system is a small part of a     5    larger group of stars and planets, called the Galaxy or the Milky Way. There are     6    of stars in the Galaxy, and our sun is only one of them.

Scientists have also     7    many other galaxies in the universe. They are very far and their light has to travel for many years to     8     us. So how     9     is the universe? It is     10    to imagine.

know     life     different     back     and     interesting     sign     real     find     they

The planet Mars is the closest and most similar planet to Earth. It is very    1    to scientists. For example, Mars has seasons with    2    weather, but other planets have the same temperatures all year round. Was there    3    on Mars?

To find out, scientists need    4    if Mars ever had water. In 2004. two robot explores (探测器), or 'rovers', called Spirit and Opportunity were sent to look for    5    of water. These rovers can drive over rocks    6    all kind of rough ground. They can also use cameras and send photos    7     to Earth. First, the two rovers found chemicals and patterns (图文) in the rocks that were probably made by water. Then, they moved to another area and    8    other rocks which may have been created by water. Now scientists think there was probably water on the planet long ago. Today       9    are still not sure if there was life on Mars. They    10    need more information to decide. The discoveries of the two rovers answered some old questions, but they also brought up many new ones.