Do you know astronauts’ everyday life in space? They also need to eat, _________, exercise and relax. They do the same thing as us, but they do them _________.

On the earth, we put food on a plate and put _________ in a glass. Gravity (重力) holds the food down and keeps the water in the glass. There is almost no gravity in space and food can fly away, _________ astronauts must eat and drink carefully.

Sleeping is very different in space. Some astronauts like to float (漂浮) in the air, but most say _________ they like to be in a sleeping bag. They tie (系) the bag to a wall so that they won’t float away at night.

Exercise is very important in space. On the earth, your legs carry your body, _________ in space, astronauts float, so they do not use _________ legs often. This is very bad _________ their legs, so they must exercise for thirty minutes every day.

After a day’s work, astronauts can’t wait _________. They may listen to music, read, watch films, play games, or __________ a few minutes talking to their friends and family on the radio. Sometimes they only enjoy floating in the air.

We have always been interested in the moon. Two thousand years ago, people already knew that the moon _________ around the earth and where it would be in the sky at different times of the year. At that time, everything about the moon was learned by _________ it carefully in the sky.

When scientists could use telescopes to study the moon more closely, their ideas began to _______. They could see that the moon was made of rocks. Most scientists thought moon rocks would be different from those on the earth. This was _________ they believed the moon had once been a planet that had been caught in the earth’s gravity (引力) millions of years earlier.

In 1969, moon rocks were finally _________ to the earth and studied. To their surprise, scientists found that, except water, the moon and the earth were made of the same things. Once again new ideas were needed for this new information.

After years of study, most scientists now think that the moon was once part of the earth. They believe very early in its history, maybe 4 billion years ago, something about the size of Mars hit the earth. This _________ billions of rocks into space around our planet. These rocks _________ joined together and after many years became the moon.

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.