Elephants on the coast of Thailand are acting strange.They stamp their feet and motion toward the hills.The sea draws back from the beaches.Fish fall heavily in the mud.Suddenly,a huge wave appears.This is no ordinary wave.It is tsunami!

    Tsunami waves are larger and faster than normal surface waves.A tsunami wave can travel as fast as a jet plane and can be as tall as a ten-story building.Imagine dropping a stone into a pond.The water on the surface ripples（起涟漪）.A tsunami is like a very powerful ripple.Tsunamis begin when the ocean rises or falls very suddenly.Large amounts of seawater are displaced.This movement caused huge waves.

    For a tsunami to occur,there must be some kind of force that causes the ocean water to become displaced.Most tsunamis are caused by underwater earthquakes.However,volcanoes ,landslides（塌方）,large icebergs,and even meteorites（陨石）are capable of causing one of these mighty waves.

    Tsunamis are extremely powerful.Ordinary waves lose power when they break.Tsunami waves can remain powerful for several days.Because tsunami waves are so strong,they can kill people,damage property,and completely ruin an ecosystem in just one hour.

    Scientists have no way of predicting when a tsunami will hit.However,if a powerful enough earthquake occurs, scientists can send out a warning or a watch.A warning means that a tsunami will very likely hit soon.A watch means that conditions are favorable for a tsunami.When people are informed of a watch or a warning,they have more time to prepare.It is best not to get caught unaware when a tsunami is on the way.

    How did people in ancient China change their luck? Most of them would take the exam, Keju, which began during the Sui Dynasty and lasted for 1,300 years before it was ended in the Qing Dynasty.

    Keju, the early “gaokao”, played a very important role in choosing qualified persons to work for the king.

    The Keju exams were mainly based on classical literature(文学) and philo- sophy. Poetry was very important in earlier Keju exams, and later Keju focused more on writing.

    All candidates had to write an article explaining ideas from those books, which was called Eight Part Essay. Two sentences were required at the start of the article, about the main idea of the title, which was called “to clear the topic”. The exams also focused on more practical matters.  

    Most candidates in ancient China had to go a long way to the capital city for the exam. As transportation in ancient times was not developed, they usually went to the capital on foot, and some took several months to reach the capital.

    The exam was held once every three years and it was made up of four levels: the county examination, provincial examination, academy examination and palace examination. Candidates had to first pass one level in order to take part in the next level. Each examination would take from one to three days to finish, and they were locked in a small room and received cold meals.

    On the exam day, candidates had to first go through safety check. They had to let their hair loose so that it could be checked and their trouser legs, shoes and socks, even bottoms were also checked.

    It was an oral English class and in front of us was standing our teacher Lila Betray, who was a university student from the US. Somehow we came to the point whether any of us could sing an English pop song in front of the class. You know, maybe three or more out of ten Chinese students are shy in class. As a result, there was silence in class for quite a while, which made everybody feel rather embarrassed (尴尬的), including the teacher.

    I was a shy boy. However, just at that moment, a great idea struck me suddenly. “Seize the enjoyment! Seize the chance. Yes, there couldn't be a better chance.” I said to myself. “Why not seize it? Why should I have always to be the guy regretting missing the opportunity just because of shyness? Yes, maybe I should have a try!”

    So, I raised my hand. And I remember that it took me quite a while to think what the song's name was. Though I sang no more than five sentences because of forgetting the lyrics (歌词), their clapping hands told me that I did the job well. Later, I got a gift and I was really happy.

    I think that is one of the most unforgettable moments in my life. Through this experience, I've also got to know that we should believe that we can do the job well, no matter how difficult it seems for us. Just have a little more courage.

    All over the world, children in hospital are being treated with a new kind of medicine：Laughter. Lucy is 23 and works for Theodora Children's Trust. She is one of many clown (小丑) doctors who bring a smile to the faces of sick children.

    “I'm a Theodora clown doctor. I call myself Dr Looloo. I spend two days a week in children's hospitals, making funny faces, telling jokes, and doing magic tricks. As I walk into the wards(病房) I blow bubbles, shake hands with the kids, and make up nonsense songs for those children well enough to sing. I take special balloons to make 'balloon animals' and tell funny stories about them.

    I'm naturally a very cheerful person. I've always been a clown. In fact my father's a clown and I started working with him when I was eight years old. I knew it was just the job for me and I became a clown doctor because I think it's a great way to cheer up sick, frightened children in hospital.

    Being a clown in hospital is very tiring both physically and emotionally. We have to learn not to show our feelings, otherwise we'd be useless. Clown doctors are sensitive but this is not a side most people see. To the children we're happy all the time. I'm still learning to allow myself to feel sad occasionally. There working with a very sick little girl from Bosnia who speaks no English, so our only common language is laughter.

    At weekends I participate in events to raise money for Theodora Children's Trust. It's a charity, so we are paid with the money people give. Being a clown doctor makes the worries of everyday life seem small. All in all I feel honoured to do this job.”

    When I was young, I read many kinds of books, including fairy tales. Most of the books described heroes who were handsome and heroines who were beautiful. So, I believed I had to be beautiful if I wanted to become a great person.

    As I grew up, I began to realize outer beauty was not so important to make someone good. I remember a friend of mine, Janie, who was so beautiful that every classmate wanted to talk with her, but she was very arrogant(傲慢的).

    She believed that she could do everything she wanted because she was so beautiful, but she lost friends one by one. My poor friend! But she learned a good lesson: inner beauty is more important than outer beauty. After she learned that, she changed her attitude and made friends again.

    Whenever I see TV advertisements, I feel that these things make us believe beauty is very important—especially physical attractiveness. Although we say that inner beauty is more valuable, we often look to plastic surgery to make us more beautiful. There seems to be a boom(流行) in plastic surgery. It is surprising to realize the number of people who try it is increasing day by day.

    We know good-looking guys usually get higher scores on job interviews. So, what is real beauty? I want to say that inner beauty is the real one because if someone has beauty in his soul, he looks like a really beautiful person.

    The beauty looked at with eyes doesn't last forever. Instead of concentrating on outer beauty, we should concentrate on inner beauty. The point is that inner beauty is more important than outer beauty. So, if we make the effort to make our minds beautiful, we'll be happier.

Scientists at the Department of Energy's Lawrence Berkeley National Laboratory and the California Institute of Technology have-in just two years-nearly doubled the number of materials known to have potential for use in solar fuels.

They did so by developing a process that promises to speed the discovery of commercially viable (商业可行性) generation of solar fuels that could replace coal, oil, and other fossil fuels.

Solar fuels, a dream of clean-energy research, are created using only sunlight, water, and carbon dioxide. Researchers are exploring a range of possible target fuels, but one possibility is to produce hydrogen by splitting water.

Each water molecule (分子) consists of one oxygen atom and two hydrogen atoms. The hydrogen atoms are extracted, and then can be reunited to create highly flammable hydrogen gas or combined with CO 2 to create hydrocarbon fuels, creating a plentiful and renewable energy source. The problem, however, is that water molecules do not simply break down when sunlight shines on them-if they did, the oceans would not cover most of the planet. They need a little help from a solar-powered catalyst (催化剂).

To create practical solar fuels, scientists have been trying to develop low-cost and efficient materials that perform the necessary chemistry using only visible light as an energy source.

A new method was developed through a partnership between the Joint Center for Artificial Photosynthesis (JCAP) and Berkeley Lab's Materials Project, using resources at the Molecular Foundry and the National Energy Research Scientific Computing Center (NERSCC). JCAP focused on developing a cost-effective method of turning sunlight, water, and carbon dioxide into fuel. It is led by Caltech with Berkeley Lab as a major partner. The Materials Project is a program based at Berkeley Lab that aims to remove the guesswork from materials design in a variety of applications.

"What is particularly significant about this study, which combines experiment and theory, is that in addition to identifying several new compounds for solar fuel applications, we can also learn something new about the basic electronic structure of the materials themselves." says Neaton, the director of the Molecular Foundry.