When Justin Tong was a child, other kids felt sorry for him. His parents always had him doing lots of housework such as carrying out the rubbish and sending newspapers. But when he grew up, he was better off than his childhood friends and lived a happier and healthier life.

This is the finding of a 40-year study that followed the lives of 456 children in London. It showed that the children who had worked hard in childhood had a richer and a happier future. "Children who worked in the home or community gained competence(能力) and came to feel they were worthwhile members of society," said Daniel Brown, the psychologist(心理学家) who made the discovery. "And because they felt good about themselves, others felt good about them."

Brown's study followed these children in great detail. Interviews were repeated at ages 25, 31 and 47. Under Brown, the researchers compared the children's mental-health scores with their childhood-activity scores. Points were awarded for part-time jobs, housework, effort in school, and ability to deal with problems.

    Working at any age is important. Childhood activities help a child develop responsibility, independence, confidence and competence — the underpinnings (基础) of emotional health. They also help him understand that people must cooperate and work toward common goals. The most competent adults are those who know how to do this.

    Yet work isn't everything. As Tolstoy once said, "One can live magnificently in this world if one knows how to work and how to love, to work for the person one loves and to love one's work."

    Many people may not know the name of the girl in the photo but her large and clear eyes can often be seen in newspapers.

    Her name is Su Mingjuan and now she's more than 30 years old. In 1991, when Su was only 8 years old, Xie Hailong, a photographer from China Youth Daily, took a picture of her in a classroom which was in a poor condition in Anhui.

    The photo was later used as a poster for Project Hope. It has become a symbol of the country's efforts to make more people realize the importance of education. Her large and clear eyes crying for knowledge in the picture have moved a big number of people across China, who have donated (捐赠） money to help children continue their schooling since then.

    Having received help from Project Hope, Su herself has also been helping poor students. She began to study at Anhui University in 2003. After entering college, she wrote to the China Youth Development Foundation, the organizer of Project Hope, to transfer her living allowance (补助) of 900 yuan a term to other students in need. And she began to do part-time jobs to make money. After graduation, Su found a job in a bank. Since she started working, she has donated 1,000 yuan every year.

    Since it was started in 1989, Project Hope has received about 13 billion yuan in donations from home and abroad. And the money has been used to build over 19,000 primary schools and help over 5. 5 million children.

    Charlie and his family don't always live in their house. Sometimes they live in a houseboat. There are 4 rooms in the bottom of the boat. One of them is his parents' bedroom. Another one is his bedroom. Then there is a kitchen and a bathroom. Charlie's bedroom is small, but he likes it very much. It has a small window. He doesn't open it because it's under the water. When the boat is in the water, Charlie can look out of his window and see many fish under the water. Once he saw an old car under the water. He thought it was funny to see the fish swim through the car windows.

    In the school year, Charlie's family keep their boat on the bank (岸) of the lake. In summer Charlie and his family often take their boat out to the middle of the lake. They stay on the lake for a few weeks. Then they go fishing for their food. Charlie's mother grows vegetables in pots on the boat, so they also have vegetables to eat. When it is very hot, they jump into the water and go swimming. Charlie thinks a houseboat is the best place to live in.

Astronauts would face dangers both getting to and surviving (生存) on Mars. Let's learn about surviving a trip to Mars.

What would it take to keep people safe and healthy on a trip to Mars? Scientists are already working on it, though the trip may be many years later.

Over the last 60 years, many spaceships have flown by orbited（沿轨道运行）and even landed on the Red Planet. However, machines cannot replace humans. That's why the United States, China and other countries want to send people to Mars. But surviving on this trip would not be easy.

A trip to Mars would be the farthest journey in human(人类) history. Mars is about 225 million kilometers away, so it would take astronauts at least 180 days to reach there. However, it only takes a few days to get to the Moon.

Space travel is dangerous. For one thing, staying in space for long periods makes the human body weak. Also, it puts pressure behind the eyes and causes eye problems. But gravity(重力) machines could help.

Then there's space radiation(辐射) to worry about. It is bad for astronauts when they have long journeys. Scientists are working out the issue. They have found that taking certain vitamins can help.

Astronauts will have to pack light to lift off from the earth. But they won't be able to get the things they need easily. Astronauts on the space station practice for this by growing lettuce and other food in space. Engineers are developing 3D printing techniques（技术）which can allow future Mars astronauts to build what they want.

Life in the future will be different from life today. Many changes will happen. But what will the changes be?

The population (人口) is growing fast. There will be more people in the world and most of them will live longer than people live now. 

Computers will be much smaller and more useful, and there will be at least one in every home. And computer studies will be one of the important subjects in school then. People will work fewer hours than they do now and they will have more free time for sports, watching TV and travelling. Travelling will be much cheaper and easier. 

There will be changes in our food, too. More land will be used for building new towns and houses for all the people. Then there will be less room for cows and sheep, so meat will be more expensive. Maybe no one will eat it every day. Instead (相反), they will eat more fruit and vegetables. Maybe people will be healthier. Work in the future will be different, too. Robots will do dangerous and hard work. Because of this, many people will not have enough (足够的) work to do. This will be a problem.