Many animals hide to stay alive. They hide in many ways. Some animals hide in leaves; some animals hide in snow. Usually their colors or shapes help protect them. It's hard to see an Arctic bear in snow. Its white fur helps protect it. Chameleons(变色龙) can hide by changing colors. Their skin turns the same color as what is around them. Some chameleons can change colors in five minutes.

    Many animals try to look bigger than they are to stay alive. Some animals can make other animals think they are very big. If they look very big, animals that are looking for food will run away. Bears can walk on two legs. They look very, very scary. Some animals will run away from them.

    Many animals try to stay around other animals. This helps them stay alive. Zebras stay close together so that they can help each other look out of danger. Seeing many stripes at once can also confuse animals that want to eat them. Some birds stay in a circle, each toward a different direction. In this way they can also help each other stay alive by looking around for animals that many want to eat one of them.

    Many animals are in danger of dying out. We can see the number of animal species decreases faster and faster and this trend will continue. From 1980 to 2010, at least I million animal species disappeared. Worse still, more and more wild animals are in great danger. It is not a piece of terrible news; it is a fact, a harsh reality. Unfortunately, we may not see these animals in the near future.

    Why is the number of animal species declining year by year? Apparently animals have become victims of fashion industry. Animal skin has been used to make fashionable clothes and these clothes are sold at a high price. So some greedy people begin to kill animals in a large quantity.  This irresponsible behaviour not only breaks the balance of nature but also endangers the living environment of human beings.

    As far as I am concerned, something must be done to stop this illegal action. We believe "no buying, no killing". First, we must make concerning laws to protect these animals in danger.  Second, we must take some measures to protect animals effectively. Animals are our friends and part of our environment. Third, we should raise people's awareness to protect animals and our environment.  In this way, we can build a harmonious society and ensure a sustainable development.

    Life in space is much different from life on earth. How do astronauts live in space?

    Eating    In the past, astronauts could only eat small pieces of dried food. But now they are able to eat more everyday food like fruit, vegetables and ice-cream.

    Sleeping    All the people on the ISS（国际空间站）have their own rooms. They should be tied（系）to their beds, or they'll fly away! That seems like a hard way to sleep, but astronauts say sleeping is really not too bad.

    Exercising    This is more important in space than on earth. Astronauts exercise on bikes and other machines（机器）for about two hours every day. That way, they can still be healthy when they get back home.

    Having fun    Astronauts can read books, play cards, listen to music or send emails to their friends and families when they aren't working. Sometimes they just sit and look out of the window. It's also much fun!

    Animals, including insects, do not have a language like ours. They do not talk to each other in words and sentences. But if we watch them, we can see that they do have ways of communicating with each other.

    Can you see the rabbit's tail which is moving up and down? When rabbits see this white tail moving up and down, they run too. They know that there is danger. The rabbit has told them something without making a sound. It has done this by using its body language.

    Many other animals use this kind of language. When a cobra is angry, it raises its hood and makes itself look fierce. This warns other animals. When a bee has found some food, it goes back to its home. It cannot tell the other bees where the food is by speaking to them, but it does a little dance in the air. This tells the bees where the food is.

    Some animals say things by making sounds. A dog barks, for example, when a stranger comes near. A cat purrs when pleased. Some birds make several different sounds, each with its own meaning. Sometimes we human beings speak in the same way. We make sounds like "Oh" or "Ah!" when we are frightened or pleased or when we drop something on our toes.

    But we have something that no animals have—a large number of words that have the meanings of things, actions, feelings or ideas. We are able to give each other all kinds of different information in words and sentences, which no other animals can do. No other animals have so wonderful a language as we have.

    Are you shy? If you are, you are not alone. In fact, close to 50 percent of people are shy. Almost 80 percent of people feel shy at some point in their lives. These days, shyness is becoming more and more common. Now, scientists are trying to understand shyness. They have some interesting ideas about why people are shy.

    Is it possible to be born shy? Many scientists say yes. They say 15 to 20 percent of babies behave shyly. These babies are a little quieter and more watchful than other babies. Interestingly, these shy babies usually have shy parents. As a result, scientists think that some shyness is genetic.

    Family size might cause people to be shy as well. Scientists at Harvard University studied shy children. They found that 66 percent of them had older brothers and sisters. The scientists said that these children were often bullied(欺侮) by their older brothers and sisters. As a result, they became shy. At the same time, children with no brothers and sisters may be shy as well. Growing up alone, they often play by themselves. They are not able to learn the same social skills as children from big families.

    You may also be shy because of where you were born. When scientists studied shyness in different countries, they found surprising differences. In Japan, most people said they were shy. But in Israel, only one of three people said so. What explains the difference? One scientist says the Japanese and Israelis have different opinions of failure. In Japan, when people do not succeed, they feel bad about themselves. They blame (责备) themselves for their failure. In Israel, the opposite is true. Israelis often blame failure on outside reasons, such as family, teachers, friends, or bad luck. In Israel, freedom of opinion and risk-taking are strongly supported. This may be why Israelis worry less about failure and are less shy.

    For shy people, it can be difficult to make friends, speak in class, and even get a good job. But scientists say you can get over your shyness. They suggest trying new things and practicing conversation. And don't forget—if you are shy, you are not the only one.