Earth is our home. It has air that we can breathe(呼吸). It has water for us to drink. It has plants and animals that we can eat. Earth is not too hot or too cold for us. It has everything we need to live.

    We are on earth, but we call see things that are not on earth. Early in the morning, we can see the sun comes up. All day, the sun seems to move across the sky. Later in the day, we can see the sun goes down. But the sun is not really moving around us. We are the ones who are moving. Every morning, we turn towards the sun. Every night, we turn away from it. Every year, we go around it. Earth is our spaceship. All of us in the spaceship are riding around the sun.

    At night, we can often see the moon and stars. From earth stars look like little points of light because they are so far away. But stars are really big. A star is a great mass of burning gas. It gives off light and heat. Our sun is a star.

    There are eight planets moving around our sun. Earth is the third planet around the sun. Some of the planets have moons. A moon goes around a planet just as a planet goes around a star. Earth has only one moon. Some planets have more.

    Can you imagine astronauts' everyday life in space? They also need to eat,  1 , exercise and relax. They do the same things as us, but they do2 differently.

    On Earth, we put food on a plate and water in a glass. Gravity(重力) holds the food down and keeps the water in the glass.  3 there is almost no gravity in space, so food can float(漂浮) away, and astronauts must eat and drink4  .

    Sleeping is very different in space. Some astronauts like to float in the air, but most like to be in a 5bag. They tie the bag to a wall 6 they won't float away at night. Exercise is very important in space. On Earth, your legs 7 your body, but in space, astronauts float. So they do not use their legs often. This is very  8their legs, so they must exercise for thirty minutes every day.

    After a day's work, astronauts relax. They may listen to music, read, watch films, play games, or talk to their friends and families  9  the radio. Sometimes they just enjoy 10 in the air.

-- Sure,          .

-- Of course. I           180 yuan on it.