There's no pizza on Mars, but scientists have found a way to solve this problem for hungry astronauts: a pizza printer! NASA has developed a machine that "prints" food. They showed a model of the printer in Texas, US.

    How does it work? Cartridges(墨盒) can be filled with powdered dough, cheese, sauce, water and oil. Put these ingredients onto a printer bed. The printer bed, which gets hot from below, cooks the food as it's being printed.

    Most of the ingredients are powdered, so they call be sent into space and stored for many years without going bad. The food powder can mix with water and oil when they're being printed.

    In outer space, there are fewer choices for astronauts for dinner. Most of their foods—even things like beef—are eaten from bags as powder. Scientists hope me new food printer can be used to make more delicious food in outer space.

    The printer isn't only used in outer space. Scientists think it could be useful on Earth too. People can make meals at the dinner table according to their different needs.

    One of the hottest places on Earth is Death Valley. It's a desert valley in North America. The animals in Death Valley don't use technology to keep cool. They have special abilities that help them live there.

    During the day in Death Valley, it gets hotter than 100°F. The kangaroo rat rests all day in a hole in the ground. It covers the hole with grass to keep out the heat. The kangaroo rat comes out at night when it is cooler. This little rat is also very good at saving water. It gets all the water it needs from the food it eats. The Sun makes the desert sand very hot. One snake, called the sidewinder, can solve this problem. When it travels, the sidewinder bends (弯曲) its body into a "W" shape. Then it uses the bottom parts of the "W" like legs and walks sideways (向一侧). That way it touches only a little of the sand at a time, so the hot sand doesn't bum the snake. This strange way of moving is how the sidewinder got its name.

    A lot of water in the desert is too salty for most animals to drink. One kind of fish, the desert pupfish, can live in these salty water because it can drink the salt water.

    Smokejumpers are special firefighters. They jump from planes into areas that are difficult to reach by car or on foot, like the middle of a mountain forest. They race to put out fires as fast as they can.

    At a fire site, smokejumpers first check the land and decide how to fight the fire. They try their best to stop a fire from spreading. Using their tools, smokejumpers clear the land of burnable things like dry grass and leaves. They usually carry some water with them.

    In the US, although most smokejumpers are men, more women are joining. The important thing is that your height and weight must be within a certain range(范围). For example, smokejumpers in the US must be between 120 and 200 pounds, so they don't get hurt when they land, or get blown by strong winds.

    Smokejumpers must also be able to live in the wilderness. In Russia, many smokejumpers know how to find food in the forest and make simple tools.

    The work is dangerous, and the hours are long. But for smokejumpers, smokejumping isn't just a job. They love being able to jump out of planes, fight fires, and live in the forest. As 28-year-old proud Russian smokejumper Alexi Tishin says, "This is the best job for brave people."

    One Sunday morning, my husband and l went into a store. While paying, I heard the cashier (出纳员) say "How are you today?" as usual. I looked at her and said. "Not bad. And how are you doing?" Then I waited kindly for an answer.

    She was a little surprised at first, but then she looked sad. "My grandfather is in hospital. He has a terrible illness. I know he is 91, but…" She began to cry.

    "Don't worry too much. He will be better soon." I said.

    "Thank you!" she replied.

    Several weeks later. I went to the store again. I wanted to buy a birthday gift for my father. I saw the cashier again. I stood in her line. After the usual "How are you?", I asked quietly, "I hope this is not a bad question, but how is your grandfather doing?"

    She wondered at first why I asked such a question. Then she smiled and started telling me how brave he was. She was excited, and even after I finished paying, she kept talking, sharing her happiness with people around.

    I was surprised at how something so small meant so much to her. Taking time to listen after we ask "How are you?" is such a small action, but it is helpful and important to others!

    As space science develops, man has learnt more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger as well as success.

    Scientists have found out that the radiation is the greatest danger to spacemen in space. When spacemen are working in space, they are in danger of the radiation from the Sun and other stars, which is bad for their health.

    Space rubbish is also a great danger to spacemen. It's reported that there were 9,000 man-made things flying in space. About 30% of these are satellites, 10% are spaceships, and the rest space rubbish. A small piece of these can knock a spaceship window and cause some damage.

    Scientists are watching and reporting any possible danger all the time. They are working to deal with space rubbish. Although space is really dangerous, it interests many people on Earth. In the near future, it may become possible for people to spend a few days in a space hotel. We may even choose to leave the Earth and live in space in a few years. So we should do something to help improve the space environment.

    An old man was going home late one night with his horse and cart after a day's hard work. When he was not far away from his house, the light on the cart went out. He tried but could not repair it. He was near his home, and so he went along the road without a light. When a policeman saw this, he stopped the old man.

    "Where is your light?" asked the policeman. "No man may take a cart along the road at night without a light. You know that. You have broken the law." "I had a light, but it has just gone out," said the old man.

    "I don't believe that story. What's your name and where do you live?" asked the policeman. "Please don't write down my name," said the old man. "My home is just there. You can see it from here. I had a light nearly the whole way."

    "You came all the way without a light. What's your name?"

    The old man quickly took the policeman's hand and put it down on the top of the light. The light was still hot and burnt the policeman's hand. The policeman jumped and he was very angry. "Now, what do you think?" said the old man. "Did I come all the way without a light?"

    Most people have heard of the Great Wall, but not many people outside China know about the Grand Canal. This man-made waterway is known to the Chinese as the Beijing-Hangzhou Grand. Canal. It is the longest as well as one of the oldest canals in the world and a place of interest. It's 1,797 kilometres long and some parts of it are more than 2,000 years old. Starting from Beijing, it passes through Tianjin and the provinces of Hebei, Shandong, Jiangsu and Zhejiang to the city of Hangzhou. The Grand Canal links the Yellow River and the Yangtze River.

    It was built as a way to transport grain from the rich agricultural land in China's south to cities in the north. In fact, it's not one canal, but a system of canals and rivers linked together. It's still an important part of the transport system in China. Thousands of ships use it every day to transport grain and many other types of goods.

    The Chinese government has done new work on the Grand Canal. It has made Darts of it deeper, so bigger ships can use it. The canal also helps to move water. There is a lot of rain in the south of China, but not as much in the north. The canal can carry millions of liters (公升) of water from the south to the north.

    The Grand Canal is much less famous than the Great Wall, and not very many tourists visit it. But it's possible to go on a cruise (乘船游览) along some of the oldest parts of the canal. Passengers on these cruises can see beautiful parts of China that other visitors don't see.

    It was Saturday again. Grace and Karen disliked Saturdays. That was another thing the twins had in common. They shared the same clothes and tied their hair in the same manner. In fact, it was hard for their classmates and teachers to tell them apart sometimes.

    Unlike their classmates, they had to get up early every Saturday to prepare for their lessons. Grace had to attend the art lesson and Karen had to attend her ballet lesson. "How I wish I could do something different today", said the twins with one voice. All at once, an idea came to Grace and Karen at the same time.

    "How would you like to be me for a day?" they asked each other. It seemed like a wonderful plan to them. After giving each other a description of their own friends, Grace put on Karen's ballet dress while Karen put Grace's brushes and paints into her bag. Then they left for their classes.

    When the art lesson started, Karen was lost. Unlike Grace, Karen was poor at drawing. When the art lesson finally ended. Karen didn't dare to hand in her work.

    Meanwhile, Grace was struggling in the ballet class as well. As she had no idea about the dance steps, she had to follow her classmates blindly. As a result, she kept knocking into them. Their ballet teacher became impatient with her, "Karen, you should remember the basic steps. You can't rely on copying what others are doing."

    When Karen and Grace got home, they were tired out. They decided that they would never try to be someone else they were not. It seemed that the grass was not always greener on the other side.

    We produce lots of rubbish everyday.  (take) away a city's rubbish is a big job. Every day trucks come into a city  (collect) the rubbish. Most of it is made up of things we can't eat  use. If we keep these things, we will have a mountain of rubbish soon.

    In some cities the rubbish.  (carry) outside the city to a dump(垃圾场). The kitchen rubbish is broken into small pieces and sent into a sewage system(污水处理系统).  sewage system takes away the used water  toilets and other places.

    People usually use some earth to cover the dumped rubbish. Later, grass may be planted on the land. After all of these, the place looks much  (clean) than before. With the beautiful environment in front of  (we), it's hard to imagine that it used to be a rubbish dump. But actually it is not  (health) to stay in such a place for a long time.

    In order to protect the cities, the rubbish is burnt in special places. The fire burns everything  the metal. Sometimes the metal can be used again in factories. In those factories, the metal is made into different kinds of products.

    One afternoon, I went into an art museum while waiting for my husband. I hope  (enjoy) the works of art quietly.

    A young couple walked in front of me and talked  the paintings between themselves all the time. The lady did almost all the talking, but the man kept  (listen) to her. I thought the man was very patient because nobody would like to be bothered (打扰) while enjoying the paintings.

    I met them several  (time) as I moved through the different rooms of the art museum. Each time I heard her talking, I moves away  (quick).

    I was paying for some gifts at the museum shop when the couple walked slowly to the exit (出口). Before they left, the man  (take) out a cane (拐杖). Then he tapped (轻敲) his way to the coatroom to get the jacket for his wife.

    "He is a brave man," the worker of the shop said. "He decided not to change his life after his eyes got hurt.  he is blind now, he never gives up. He and his wife come here whenever there is  new art show."

    "But what can he get out of the art? He can't see!" I asked.

    "You are wrong. He sees a lot, more than you and I do." The worker said, "His wife describes every painting so he can see it in  (he) mind."

    I fell silent. Then I realized that I learnt something about  (patient), courage and love that day.