Look at the koala! It is 1 lovely that I want to touch it. How much do you know about koalas, especially a baby koala? Let's look at it.

    A newborn koala is smaller than a peanut. For the first few months the baby 2 inside its mother's pouch(育儿袋), and drinks its mother's milk.

    By the age of 5 3, its eyes are open and it can look out 4 the pouch. It still stays there.

     About six months after the baby is born, it leaves its mother's pouch for the 5 time for a short time, but it hangs onto its mother's back.

    It is now about 500g. It comes in and out of the pouch. It keeps very close to its 6and returns to the pouch within a few minutes. Gradually the baby will stay out longer.

    By 12 months old, the baby wants to eat only eucalyptus(桉树) 7, no more its mother's milk. The mother koala begins teaching her baby which eucalyptus leaves are 8 to eat.

    A one-year-old koala can 9 on its own, 10 it doesn't often do that. Most young koalas stay with their mothers until they are two or three years old.

    The computer is fast, and never makes a mistake, while people are too 1 and full of mistakes sometimes. That's what people often say when they talk about computers. For over a quarter of a century, scientists have been 2 better and better computers. Now a computer can do a lot of everyday 3 wonderfully. It is 4 used in factories, hospitals, post offices and airports. A computer can report, decide and control in almost every field. Many computer scientists are thinking of making the computer “think” like a man. With the 5 of a person, a computer can draw pictures, write music, talk with people, 6 chess, recognize voices, translate languages and so on. Perhaps computers will one day really think and feel. Do you think the people will be 7 when they find that the computer is too clever to listen to and serve the people? No, people will make 8 use of the computers in the future. Man is always the master of the computer. The computer 9 only with the help of man. It cannot take the 10 of man.

Empathy(同情心) lets us feel another person's pain and drives us to help. Do any other animals feel empathy? Scientists recently found that rats(老鼠) do, too.

    Most people don't like rats. In many people's eyes, rats are only bad. But Jean Decety and his partners at the University of Chicago did an experiment. It showed that rats are kind, warm-hearted animals. They can feel each other's pain.

Scientists placed pairs of rats in plastic cages(笼子) for two weeks. During this time they got to know each other. Then they put one of the rats from each pair into a small container(容器) in the cages. The small container had a door. It was so designed as to fall to the side when the free rat touched it. Many of the trapped(困住的) rats squeaked(吱吱叫) to show their discomfort. The other rats of the pairs could see their suffering friends clearly.

In most pairs, the free rats would become very worried about their friends. They kept trying to save their friends again and again throughout the month. Scientists put the rats' favorite chocolate in the cages, but the rats didn't eat it until they had saved their friends successfully. Scientists also found that female rats seemed to act more empathetic than male rats.

    “The results are the first to show that rats take action in response to another's trouble,” Decety said. “Monkeys and chimpanzees have similar behavior. But unlike those animals, rats can be ready used in laboratory studies. They will help us to learn which parts of the brain lead to empathy and helping behavior and whether empathy is natural.”

    Four students are talking about the future after class.

    “In 2050, our life will be much1than it is now. The sky is bluer and water is clearer. We can2the fresh air every day. Humans and animals3the world peacefully. ” says Zhang Tao, full of hope.

    Wang Yan thinks that it is not a4to travel to the moon for a holiday. We eat healthy food every day. At that time, everyone will enjoy a5life.

    Li Yuan Yuan believes that people will have more free time because robots (机器人) will be very popular and will do many things6people. And we will build new7on other planets (星球). Maybe we can chat with each other in our new homes.

    Zhao Kai thinks that no animals will die out because of cloning (克隆). There will8no pollution (污染). The whole world will be one big9. As time10, we'll live a much easier and better life.

    Their teacher Mr. Chen tells them to work hard for their dreams and future. “Nothing is impossible. ” says Mr. Chen.

    Everyone knows water is important to all living things. But do you know these interesting 1about water?

    Without water, the Earth would look 2the Moon. People can live for a long time without food, but only 3 days without water. Scientists say about 70% of the human body is made up of water. Water4 up about 83% of our blood, 75% of our brain, and 80% of our lungs(肺）. About 95% of a tomato is water, and about 80% of an apple is water. So 5can we do to help with water problems?

    Keep a shower to 10 minutes or6 time. It helps save much water. Use a broom to sweep the floor, the stair, the garage(车库），or the sidewalk instead of water.

    7throw your used water away. Instead, you can use some to water plants or run the toilets. Use a bucket(桶）of water to 8 your bike or the family car instead of water pipes.

    Use water only9you need it. Don't leave water running. Be sure to turn the tap 10when you are not using it.

    A great way to limit(限制) your impact(影响) on the planet is to follow other animals' way of eating. Squirrels（松鼠）, 1, eat nuts close to their tree houses. Elephants eat trees or plants that 2 around. What these animals are doing is eating in season and locally. We can do the same.

    Most of our favourite fruit and vegetables have their own natural seasons. Modern farming techniques make it 3 for us to eat all kinds of things any time of the year. However, 4 we eat our food in their natural seasons, we will save more energy.

    Eating locally means eating things that are grown close to your home. It will lower the impact that you and your eating 5 have on the environment. An easy way to 6 local produce is to shop at a nearby farmer's market.

    One of the best things you can do is to grow your own food. It may seem like a lot of 7but people and communities all over the country grow some or all of their own food.

    There are many 8 to grow your own food. By doing this, you can 9 where your food comes from. Besides, you can make sure that your food is fresher. It can 10 weeks for the food to get from the farm to the supermarket.

    By growing your own food, those weeks become just days, hours or even seconds. Now that's fresh!