“Sesame Street” has been called “the longest street in the world”. That is because the television program by that name can now be seen in so many parts of the world. That program became one of American's exports soon after it went on the air in New York in 1969.

    In the United States more than six million children watch the program regularly. The viewers include more than half the nation's pre-school children, from every kind of economic, racial, and geographical group.

    Although some educators object to certain elements in the program, parents praise it highly. Many teachers also consider it a great help, though some teachers find that problems arise when first graders who have learned from “Sesame Street” are in the same class with children who have not watched the program.

    Tests have shown that children from all racial, geographical, and economic backgrounds have benefited from watching it. Those who watch it five times a week learn more than occasional（偶然的）viewers. In the US the program is shown at different hours during the week in order to increase the number of children who can watch it regularly.

    The programs all use songs, stories, jokes, and pictures to give children a basic understanding of numbers, letters and human relationships. But there are some differences. For example, the Spanish program, produced in Mexico City, devotes more time to teaching whole words than to teaching separate letters.

    Why has “Sesame Street” been so much more successful than other children's shows? Many reasons have been suggested. People mention the educational theories（理论）of its creators, the support by the government and private（私人的）businesses, and the skillful use of a variety of TV tricks. Perhaps an equally important reason is that mothers watch it along with their children. This is partly because famous adult stars often appear on it. But the best reason for the success of the program may be that it makes every child watching feel able to learn. The child finds himself learning, and he wants to learn more.

    When my son was about five or six, I traveled a lot on business. I worried all the time about what the absence might mean to him. I knew how important it was for a boy to have his father near. When I was small, the times I loved most were the special moments I shared with my father. I cherished these special moments and, to this day, hold those memories dear. I decided to create those kinds of special times for my son.

    In one of my letters home, I promised my son that I would teach him how to fly a kite and that we could go to a nearby beach and fly it as high as it would go. Through my travels I would pick up things for our kite adventure and send them to him. In my trip to Japan, I found the most beautiful blue silk with gold threads（线）woven through it. Perfect kite materials! I sent it home with a picture book that would serve as a weight.

    When I got home at night, I found him sleeping sound, surrounded by all the items I had sent him for our kite. For the next week, we started to work on our masterpiece. We had our time together in the garage, after dinner. Finally, it was finished. The blue silk made it so beautiful. He was obviously eager to fly it soon. “We'll fly it tomorrow, right, Dad?” “Yes, if the weather is right,” I explained that we needed wind to lift the kite off the ground. I was afraid that it might rain. “We'll fly it because I'm going to pray with all my heart for the best kite weather.” He was right. I will never underestimate（低估）the power of a child's prayer any more.

    My son is a dad now, with children of his own. Though we are both busy, we still try to make time for each other. The other day, we met for coffee. While paying for our coffee, his wallet dropped on the ground and something fell out. Suddenly, a flood of memories washed over us as he put back his treasure into wallet—the blue silk with gold threads woven through it.

    For twenty years, I saved all my college course notes and textbooks: that's a lot of paper.  Worse, it wasn't easy to carry them around—and trust me, they weren't light — on at least seven moves. Yet I never once looked at them. They sat in our basement, covered in a thick layer of dust. If books and papers could wonder, they'd wonder why they were still under our stairs after all those years. What were my plans for them? When would the Big Day come?

    Well, the Big Day eventually did arrive; only it was different than expected. My wife, always more accepting changes than I am, finally convinced me to clear out the entire mess.

    The pain I experienced was also unexpected. I didn't feel nostalgia(怀旧的), or suffer pains for long-lost magical moments of my education. No, what hurt me was to come across those terrible papers I'd written, reminders of poor study habits, immaturity(不成熟), and an embarrassing lack of comprehension. It was great to get rid of them. I won't have to carry those dusty, filthy(脏兮兮的) things on our next move. But it was also a clearing of personal history. Initially, I struggled with this. My books, my notes, and my papers were primary source materials, documenting an important time in my life. To clear them out was to clear out the truth. What I've learned since taking this leap is that the lesson is more important than the truth. I feel as if much of my real education during my college years isn't in the documents but now in me. So I am glad to free myself of this physical burden of carrying them around. And what's better is that I don't need to look back on those painful moments. They belong to the past.

    You might want to consider doing something similar, either under the stairs of your basement or in your mind. Not so long ago, a very smart person created a new holiday—Discardia!—to be celebrated four times a year. It's a great idea, and every time I clear things out, I feel better physically and psychologically. Discardia's slogan is “Let go of everything that doesn't make your life awesome!” What is the personal rubbish piling in your life? Clear it out and make your life awesome.

    When John was growing up, other kids felt sorry for him. His parents always had him weeding the garden, carrying out the garbage and delivering newspapers. But when John reached adulthood, he was better off than his childhood playmates. He had more job satisfaction, a better marriage and was healthier. Most of all, he was happier. Far happier.

    These are the findings of a 40-year study that followed the lives of 456 teenage boys from Boston. The study showed that those who had worked as boys enjoyed happier and more productive lives than those who had not. "Boys who worked in the home or community gained competence（能力）and came to feel they were worthwhile members of society, " said George Vaillant, the psychologist（心理学家）who made the discovery. "And because they felt good about themselves, others felt good about them."

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

    The link between what the men had done as boys and how they turned out as adults was surprisingly sharp. Those who had done the most boyhood activities were twice as likely to have warm relations with a wide variety of people, five times as likely to be well paid and 16 times less likely to have been unemployed. The researchers also found that IQ and family social and economic class made no real difference in how the boys turned out.

    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."

    If we want to find out what kind of technology people used in the past, we normally have to rely on archaeologists to find ruined buildings and parts of tools or instruments or machines. Archaeologists then try to reconstruct, sometimes with the help of computer technology, what these ancient buildings and objects must have looked like, and how they might have been made. Sometimes historians are lucky and find an ancient document with a written description of these ancient buildings and objects.

    We can understand, then, why Chinese historians were so excited when they found cave paintings which show ancient science. They found these paintings in the world-renowned Mogao Grottoes of Dunhuang City, in Northwest China's Gansu Province. There are 500 man-made caves and they have survived for at least 1,600 years. Almost all of these caves have paintings on their ceilings or walls and they date from the 4th to 14th centuries. Wang Jinyu is an expert on these cave paintings (also called frescoes) and he says: "We discovered frescoes containing scientific and technological content in almost all of the caves which have frescoes." What is remarkable about these cave paintings according to the Xinhua News Agency is that they provide evidence of "scientific and technological inventions by ancient Chinese in maths, physics, chemistry, astronomy, geography, agronomy, architecture, textiles, traffic and transportation, arms and military equipment and medical sciences".

    Among the discoveries experts have made are cave paintings showing ancient techniques of pottery making and wine production and paintings showing ancient weaving machines and then toothbrushes! The paintings also give some evidence of the lifestyle at the time with, for example, pictures of people boiling milk over 1,000 years ago. Experts believe that there is more evidence to be found, but even now the caves are a wonderful natural museum. If the walls and ceilings of the caves were all put together they would form a tapestry 20 kilometers long and 2 meters high!

    It won't be possible to travel back in time-that only happens in films-but visiting these caves would be the nearest experience you could get to travelling back in time.

Edward Ndiritu joined Lewa Wildlife Reserve in central Kenya in 1996 as a rhino monitor. Back then, illegal hunting had greatly reduced the country's black rhino population. Worried that they might become extinct, he worked his way up to lead Lewa's anti-hunting team. In 2015, his team's community-focused conservation method won him the first Wildlife Ranger Award from conservation charity Tusk.

He grew up in a village between Mount Kenya and the Aberdare Forest, which was once a wildlife route for migrating elephants and black rhinos. He saw them disappear gradually. He realized that hunting and the disruptive actions of the community were the reasons. The demand for rhino horn(角), which is very valuable in Asia, drives hunters. They are part of a big and rich crime network. There are people who help them by giving them equipment. In 2011 and 2012, Lewa had many difficulties. They lost rhinos. It was found that those involved in hunting were also linked to human smuggling(走私) and other illegal activities.

The hunting challenge has changed. Hunters now have networks, get information from the local community, and use technology like phones and motorbikes. Edward's team has adapted by using cameras, sensors, trackers, and a system that tells them when and where hunting might happen. They also work closely with the community, which is now the first 

line of defense. Lewa gives agricultural training, medical help, and business support to rural women. This makes locals more likely to report hunting before it happens.

To be a good forest guard, one needs to be honest, tough, and motivated. Edward now knows that making sure the forest guards are happy and well is very important. He is hopeful about wildlife conservation in Lewa. Funding is a problem, but organizations like Tusk are helping. Conservation is about people. Looking after those outside the reserve is necessary for the future of wildlife. Only when communities can live in harmony with the animals they see every day will there be a good future for wildlife.