Millions of years ago, there were lots of trees on the earth, because summer lasted all year round. A forest covered the earth like a green carpet（地毯）．

What was that forest like? It is not difficult to find out, because parts of that ancient forest still stand. It is known as the rain forest. Here, even in fine weather water drips through the leaves.

The largest of today’s rain forests is inSouth America. It covers about a million square miles. All the trees are very tall. The young trees are up to 60 feet high. But it is not easy for some to grow taller, because very little sunlight reaches them.

The grown-up trees are about 60 to 120 feet high. Some are even taller. The tallest trees can be 200 or more feet high.

In this forest of tall trees, not only is plant life rich, but also is animal life. At different heights (高度) live different animals. By the many noises they make you know they are there.

All living things on the earth need other living things to live. Nothing lives alone. Most animals must live in a group, and even a plant grows close together with others of the same kind.  Sometimes one living thing kills another, one eats and the other is eaten. Each kind of life eats another kind of life in order to live, and together they form a food chain(事物链). Some food chains are simple, while others are not. But all food chains begin with the sun, and all food chains become broken up if one of the links（连环） disappears .

All life needs sunlight to live on. But only plants can use sunlight directly. Plants are "factories". They make food from sunlight, water and things in the soil and air.

Plants feed all other living things. Animals can only use the sun' s energy after it has been changed into food by plants. Some animals feed directly on plants, others eat smaller animals. Meat-eating animals are only eating plants indirectly.

What about human beings? We are members of many food chains. We eat wheat, rice, vegetables, and fruits and so on. We also eat meat and drink milk. But men often break up the food chains. They kill wild animals. They also make rivers, lakes and seas dirty. When these rivers， lake, sand seas are polluted, the fish in them can not be eaten. If men eat the fish, they will get strange diseases.

Each form of life is linked to all others. Breaking the links puts all life in danger

here are four inventions.

1  when it raina, do your shoes get wet ? Of course, they do! But you can buy these clever Umbrellas For Shoes. They keep the rain off your feet.

2  Do you have to clean the floor at home? Perhaps your cat can do a better job than you. Buy these Cleaner Cat Brushes. Then you can sit back and relax!

3   Do you talk too long on the phone? Most people do ! Save time---buy the Exercise Telephone! It weighs five kilograms. Then your calls will be less than five minutes long.

4   Do your friends sometimes come up behind you and make you jump? Do cars come around the corner when you try to cross the road ? Well, it won’t be a problem if you have Two-Way Glasses. You can look at things behind and in front of you at the same time.

In choosing a friend, one should be very careful. A good friend can help you study. You can have fun together and make each other happy. Sometimes you will meet fair-weather friends. They will be with you as long as you have money or luck, but when you are down, they will run away. How do I know when I have found a good friend? I look for certain qualities of character, especially understanding, honesty and reliability (可靠).

　　Above all else, I look for understanding in a friend. A good friend tries to understand how another person is feeling. He is not quick to judge. Instead, he tries to learn from others. He puts himself in the other personˈs place, and he tries to think of ways to be helpful. He is also a good listener.

　　At the same time, however, a good friend is honest. He does not look for faults in others. He notices their good points. In short, a friend will try to understand me and accept me.

　　Another quality of a friend is reliability. I can always depend on a good friend. If he tells me he will meet me somewhere at a certain time, I can be sure that he will be there. If I need a favor, he will do his best to help me. If I am in trouble, he will not run away from me.

　　There is a fourth quality that makes a friend special. A special friend is someone with whom we can have fun. We should enjoy our lives, and we would enjoy our friendship. That is why I especially like friends who are fun to be with. A good friend likes the same things I like. We share experience and learn from each other. A good friend has a good sense of humor, too. He likes to laugh with me. That is how we share in the joy of being friends. And I know that he is looking for the same quality in me.

　　When I meet someone who is reliable, honest, and understanding, I know Iˈve found a friend!

Many people ask me what my favorite invention is. I find it very hard to answer them，because there are so many things in my life that I can choose. However，I have chosen a pen. Don't you think it's surprising?

I know that to most people a pen is very boring，but，to me，it stands for possibility(可能).There are so many things you can do with a pen. You can write a novel or a song，record information，or draw a picture.

A pen is like the beginning of something amazing to me. Every day，I write a new page with my pen，and I am slowly making a path(路)for my future. Maybe I will be a scientist and change the world with my discoveries. Maybe I'll become a musician and touch people's hearts with my music. Or perhaps I will be a writer and move people through words，or a teacher to help children grow into the kind of people that they want to be.

There are so many possibilities as to what I will do with my life，but I know that with the pen in my hand，I will write a good future for myself. Tell me what future you will write for yourself.

Wouldn’t it be great if you could walk into a store and buy life-long happiness? The idea is not as unbelievable as it sounds --- as long as(只要) whatever you buy is meant for someone else.

A recent study says that giving to others makes us happy, even happier than spending on ourselves. What’s more, our kindness might create a good cycle that leads to lasting happiness and selflessness(无私).

In this study, researchers in Great Britain asked volunteers to take a survey measuring(测量) life satisfaction. They divided all 86 volunteers into three groups. The first group was required to act a daily kindness for the next 10 days. The second group was also told to do something new each day over the 10 days. The third group received no requirements.

10 days later, researchers asked the volunteers to complete the life satisfaction survey again. The groups that practiced the kind or the new both experienced a big and nearly equal improvement in happiness; but the third group didn’t get any happier. The findings tell us that good acts exactly in fact make people feel good --- even when carried out just over a short period of 10 days. There may be special advantages to varying(使多样化) our acts of kindness, since trying new things seems to have something to do with happiness as well.

The researchers found that people generally felt happier when they were asked to remember a time they had bought something for someone else; even happier than when they remembered buying something for themselves. This happiness improvement was the same, regardless of whether the gift has cost a lot of money or only a little.

The practical meaning of this survey result could be that doing one kind act would make you happier, and the happier you feel, the more likely you are to do another kind act. This might also be used by charitable(慈善的) organizations: reminding honors of earlier donations could make them happy, and experiencing happiness might lead them to make more generous gifts.

‘‘Make-A-Wish’’is one of the world’s most famous charities(慈善）. It makes wishes come true for children who have serious illnesses. It gives them hope and joy and helps them forget about their health problems and have fun.

 It all startedin 1980 in Phoenix, Arizona. Christopher was a 7-year-old boy who was very sick .He always dreamed of becoming a police officer. Tommy Austin and Ron Cox, two police officers , made his wish come true .They gave Christopher a tour of the city in a police helicopter(直升飞机) and made a real police uniform for him.

There are four kinds of wishes children usually have:

I wish to go. Childrenusually want to travel or go to a concert, a game or a park.

I wishto meet. Children sometimes want to meet their favorite actors, singers or players.

I wish tobe. Some children wish to become actors, singers or police officers.

I wish to have.Theyoften want to have a computer, a game, a bike or many other things.

Let’s hope more wishes will come true in the future. People who work in the charity always try for the best .Almost 25,000 volunteers help, work or give money. Will you be one of them?

American people like to say “Thank you” whenever others help them. People of many other countries do so, too. It is a very good habit.

  You should say “Thank you” when someone passes you the salt on the table. When someone walking ahead of you keeps the door open for you, when someone says you have done your work well, or you have bought a nice thing, or your city is very beautiful. “Thank you” is used not only between friends, but also between parents and children, brothers and sisters, husbands and wives.

 “Excuse me” is another short sentence they use. When you hear someone say “Excuse me” behind you, you know that somebody wants to walk past you without touching you. It’s not polite to interrupt（打断） others while they are talking. If you want to speak to one of them, say “Excuse me” first, and then begin talking. You should also do so when you want to cough or make any unpleasant noise before others.

Let’s all learn to say “Thank you” and “Excuse me”.

If music makes you smart and exercise helps you to think, surely exercising to music can turn you into a person who is better at learning and understanding.

A teamof scientists from Ohio State University did experiments on 33 volunteers. They found that person who exercised while listening to Italian musician Antonio Vivaldi’s The Four Seasons did much better in language ability (能力) tests than without music.

The volunteers said they felt better after exercising with or without the music. But their improvement on the test doubled (加倍) after listening to the music during exercise.” Exercise seems to causepositive changes in the nervous system (神经系统) and have a direct result on learning ability,” said the psychologist Charles Emery. Scientists have found that music can be good for health and education. It helps relieve stress, sadness and nervousness, encourages relaxation or sleep, wakes up the body and improves memory and thoughts.

Psychologists have been using Mozart’s music, especially his violin pieces, to help children with speech disorders (言语能力紊乱). Mozart is often chosen because his music is not over-exciting. A study shouted students who often exercise to Mozart’s music go on to score higher marks in tests. With important exams drawing near, your parents will not probably allow you to listen to music. But perhaps now you have good reasons to argue with them.

Energy is everywhere and we use it every day.

Electricity is a form of energy and this is what powers the TV, mobile phone, fridge and more. Our growing need for energy is one of the problems facing the world today, because producing electricity also produces pollution. Here are some simple ways to make a big difference when using electricity.

On or off? Leaving televisions and computers on with the little red light showing still uses electricity, even though they might look like they’re turned off. To stop this you can turn them off.

Lights out. Turning lights off when you’re not in the room can save a lot of energy.

Fridge door closed. The fridge is an important part of the kitchen, because it keeps food fresh, cool and healthy. But it takes a lot of energy to keep cool, so try not to leave the fridge door open or put hot things inside.

Use the sun’s energy. An increasing number of people are fitting solar panels(镶板) to their houses. They create electricity from sunlight, which can then be used to power our homes. Solar heating panels make water hot, reducing the need for electricity or gas.