Dujiangyan is the oldest man-made water system in the world, and a wonder in the development of Chinese science. Built over 2,200 years ago in what is now Sichuan Province in Southwest China, this amazing engineering achievement is still used today to irrigate over 6,000 square kilometres of farmland, take away floodwater and provide water for 50 cities in the province.

    In ancient times, the region in which Dujiangyan now stands suffered from regular floods caused by overflow from the Minjiang River. To help the victims of the flooding, Li Bing, the region governor, together with his son, decided to find a solution. They studied the problem and discovered that the river most often overflowed when winter snow at the top of the nearby Mount Yulei began to melt as the weather warmed.

    The simplest fix was to build a dam, but this would have ruined the Minjiang River. So instead Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwater while leaving the river flowing naturally. Better still, the extra water could be directed to the dry Chengdu Plain, making it suitable for farming.

    Cutting the channels through the hard rock of Mount Yulei was a remarkable accomplishment as it was done long before the invention gunpowder and explosives. Li Bing found another solution. He used a combination of fire and water to heat and cool the rocks until they cracked and could be removed. After eight years of work, the 20-metre-wide canals had been carved through the mountain.

    Once the system was finished, no more floods occurred and the people were able to live peacefully and affluently. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams where the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally, enabling ecosystems and fish populations to exist in harmony.

    What is a big dream? {#blank#}1{#/blank#} Or, is a big dream something that provides only entertainment? Children dream big dreams, but there are three barriers to realizing dreams. They often kill them before they ever have a chance to grow.

The Self

    Immediately following the birth of a big dream, a negative self-talk takes over and gives all the reasons why it cannot happen. This inside voice is the ego (自我). It's there for protecting and should be listened to. {#blank#}2{#/blank#} Most people are influenced by the inside voice. That's why only a handful of people make their dream come true.

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    Family and friends are a lot like the ego. They want to protect those they love, so they will often list all the reasons why the big dreams won't come true. Sometimes, family and friends destroy dreams of those they love most, out of their own fear of being left behind.

The World

    If one gets past the first two barriers, one has to face the world.{#blank#}4{#/blank#} In the past, big dreamers were locked up and sometimes even killed when they were shown to the world. Fortunately, in most of the world today, big dreamers just get laughed at.

    The way to realize a big dream is with confidence and action. When children have confidence and then take action, they will be ready to accept any failure. The truth is that every great dreamer whose dreams have never seen the light of success knows failure well.{#blank#}5{#/blank#}

A. Family and Friends.

B. How big Dreams Die.

C. Does a big dream show one's future?

D. They simply fail until they succeed.

E. it is the last and the most terrible barrier.

F. Sometimes it is right, but more often it is wrong.

G. And their big dream is to be a rock star or a famous artist.

    Education is not a bystanders sport. Numerous researchers have shown that when students participate in classroom discussion they hold more positive attitudes toward school, and that positive attitudes promote learning. It is no coincidence that girls are more passive in the classroom discussion and score lower than boys on SATs.

    We found that at all grade levels in all communities and in all subject areas boys controlled classroom communication. They participated in more interactions than girls did, and their participation became greater as the year went on.

    Our research contradicted the traditional assumption that girls control classroom communication in reading while boys in math. We found that whether the subject was language arts and English or math and science, boys got more than their fair share of teacher attention. That teachers talk more to male students is simply because boys are more aggressive in grabbing their attention by calling out answers to the teachers' questions first. While girls sit patiently with their hands raised or keep silent. Psychologist Lisa Serbin and K.Daniel O'Leary, then at the state university of New York at stony brook studied classroom interaction at preschool level and found that teachers gave boys more attention, praised them more often and were at least twice as likely to have extended conversations with them.

    Years of experience have shown that the best way to learn something is to do it yourself. It is also important to give students specific and direct feedback about the quality of their work and answers. Teachers behave differently depending on whether boys or girls are active to provide answers during discussions. During classroom discussion, teachers in our study reacted to boys answers with powerful, precise and effective responses, while they often gave girls mild and unclear reactions because of their silence. Too often, girls remain in the dark about the quality of their answers. Active students receiving precise feedback are more likely to achieve academically. And they are more likely to be boys.

    This kind of communication game is played at work, as well as at school. As reported in numerous studies, it goes like this.

    Men speak more often and frequently interrupt women.

    Listeners recall more from male speakers than from female speakers, even when both use a similar speaking style and cover the same content.

    Women participate less actively in conversation. They do more smiling and gazing, and they are more often the passive by standers in professional and social conversations among peers.

    Women often their own statements into unsure comments. This is accomplished by using qualifiers and by adding tag question. These uncertain patterns weaken impact and signal a lack of power and influence.

    Only when girls are active and treated equally in the classroom will they be more likely to achieve equality in the workplace.

    For high school leavers starting out in the working world, it is very important to learn particular skills and practise how to behave in an interview or how to find all internship(实习). In some countries, schools have programs to help students onto the path to work. In the United States, however, such programs are still few and far between.

    Research shows that if high schools provide career-related courses, students are likely to get higher earnings in later years. The students are more likely to stay in school, graduate and go on to higher education.

    In Germany, students as young as 13 and 14 are expected to do internships. German companies work with schools to make sure that young people get the education they need for future employment.

    But in America, education reform programs focus on how well students do in exams instead of bringing them into contact with the working world. Harvard Education school professor Robert Schwartz has criticized education reformers for trying to place all graduates directly on the four-year college track. Schwartz argued that this approach leaves the country's most vulnerable(易受影响的) kids with no jobs and no skills.

    Schwartz believed that the best career programs encourage kids to go for higher education while also teaching them valuable practical skills at high school. James Madison High School in New York, for example, encourages students to choose classes on career-based courses. The school then helps them gain on-the-job experience in those fields while they're still at high school.

    However, even for teens whose schools encourage them to connect with work, the job market is daunting. In the US， unemployment rates for 16-to-l9-year-olds are above 20 percent for the third summer in a row.

    “The risk is that if teenagers miss out on the summer job experience, they become part of this generation of teens who had trouble in landing a job,” said Michael, a researcher in the US.

    More than 20 years ago, a skeleton called Little Foot turned up in a South African cave. The nearly complete skeleton was a member of the human family. Now researchers have freed most of the skeleton from its stony shell and analyzed the fossils (化石) and they say 3.67-million-years-old Little Foot belonged to a unique species.

    Researcher Ronald Clarke and his colleagues think Little Foot belonged to A. Prometheus (普罗米修斯南猿). Clarke works at the university of the Witwatersrand in Johannesburg South Africa. He studies fossilized humans and our relatives. Their foundings, published in four papers, have suggested the species A.Prometheus might have existed. Clarke has believed in that species for more than a decade, he found the first Little Foot's remains in a storage box of fossils in 1994. People began digging out the rest of the skeleton in 1997.

    Many other researchers instead argue that Little Foot likely belonged to a different species, which is known as A.africanus (南方古猿非洲种). Researcher Raymond Dart first identified A.africanus in 1924. He was studying the skull (头颅骨) of an ancient youngster called the Taung Child. Since then, people have turned up hundreds more A. africanus fossils in South African caves. Those include Sterkfontein, where Little Foot was found.

    The braincase is the part of the skull that holds the brain. And researchers found a partial braincase that Dart thought belonged to a different species in Makapansgat, one of those other caves. In 1948, Dart called this other species A. Prometheus, but he changed his mind after 1955. Instead, he said that braincase and another fossil at Makapansgat belonged to A.africanus. There was no A. Prometheus after all, he concluded.

    Clarke and his colleagues want to bring back the rejected species. They say Little Foot's distinctive skeleton, an adult female that is at least 90 percent complete, is solid evidence for it.

    Many of us just laugh it away when they are told incredible (难以置信的) stories about other people, but I have a deep interest in these stories and I prefer to believe they are true. Here's one I collected from a total stranger.

    "Well, I was 11 when my family arrived at Fern Lake overlooking Trail Ridge Road in Rocky Mountain National Park. It was so beautiful to look miles across the Rockies and thousands of feet below into the valley. My parents were busy getting lunch out of the trunk so I climbed over the wooden fence to get closer to the cliff edge in the hope that I wouldn't miss any beautiful sight down there.

    I started down a little hill but soon started sliding on loose pebble rocks(鹅卵石). I fell on my back, but kept going faster and faster to what seemed the edge of the world (a 2,000 foot drop). In seconds I knew I was going to die. My feet and legs went first over the edge at a high speed. Then suddenly I felt two hands push hard on my chest and stopped me dead. My heart was racing and I slowly inched my body back to where I finally could make it back up the hill.

    My father was waiting there and screaming at me for doing such a dangerous stunt (特技). I tried to tell him and my mom about the hands that held me back, but to this day they don't believe me. They thought I was just trying to get out of trouble with a made-up story.”

    We parted ways, but I assured her that I believed every word of her story. I could see a little surprise and happiness on her face.

    That's why I always ask people to share their miracles (奇迹). Each real story makes my days full of hope and gratefulness.