The universe (宇宙) is everything out in space. Nobody _______ how large the universe is. When we talk about the universe, we _______ the Earth, the Sun, the Moon and all the stars, and the space between them.

Now let me tell you something about the _______. It is like a large ball. It _______ around the Sun. And _______ and land cover it. If you are in a spaceship and _______ the Earth from space, you will find that there are some large blue parts. They are the seas and about 70% of the Earth’s surface (表面) is water.

We live on the outside part of the Earth. Around us is the air. It takes the Earth 24 hours to turn in a full _______. When you see the Sun shining _______, it’s the day for you. But when the Earth turns you away from the Sun, everything around you becomes _______.

Can you tell me something else about the universe? I’m ________ in it and want to learn more about it.

If you are dreaming of becoming an astronaut after you grow up, get started now! An astronaut needs a strong body and mind. Shenzhou XIII astronauts are able to live upside-down （倒立）. They do this not just during sleep, but also when eating and going to the toilet. Before they ________ space, they had lots of practice. Each upside-down training time lasted for 20 days.

Chinese astronauts aren’t just spaceship ________ but also machine repairers（修理工）and scientists. They have to know every part of the spaceship and how it ________. If something goes wrong, they’ve got to know ________ repair it. Also they do scientific experiments in space.

Shenzhou XIII astronauts know how to live in ________. They took a knife, a gun（枪）and some dye（染色水）________ them into space. If they land in forests, the knife and gun can protect them from wild animals. If they ________ the sea, the dye can colour the seawater around them yellow. This can drive ________ sea animals away.

Shenzhou XIII astronauts can’t get dizzy（眩晕）. A spaceship is not a plane. When it ________ the extra gravity force（额外重力）can break people’s bones（骨头）.

Astronauts must have strong bodies for this. They can’t get a headache or be sick. Because they have to ________ many things. They’ve got no time for sickness. Do you still have a long, long way to go?

Believe it or not, the day when you can go to the moon is coming soon. You can go into space _______ space shuttle (太空船). It _______ about three days for the shuttle to go from the earth to the moon. The shuttle flies a long way to a space station. You can stay there for a short rest and then it will _______ you to the moon.

Now you can jump out of the shuttle. But you mustn’t take off your spacesuit (太空服), because it is very hot in the daytime and very cold at night on the _______. The moon is much smaller than the earth. Things are _______ on the moon than they are on the earth. You can jump high every time you take a step. You will find that it is never tiring to walk on the moon. You don’t need to take an umbrella or a raincoat with you _______ there is no rain on the moon. You can hear _______ because there is no air on the moon. And there are no animals or other living things there.       

The moon moves more _______ than the earth, so one day on the moon is as long as two weeks on the earth and one night is just as long as two weeks on the earth. What could you do in _______ long days and nights and in a silent world? Now ________ are trying to make the best of the moon. But our earth is really a far better place to live, as long as we take good care of it.