What will power your house in the future？Nuclear, wind, or solar power？According toscientists at the Massachusetts Institute of Technology(MIT)in the US, it might beleaves—but artificial(人造的)ones.

    Natural leaves are able to change sunlight and water intoenergy. It is known as photosynthesis(光合作用). Nowresearchers have found a way to imitate this seemingly simple process.

    The artificial leaf developed by Daniel Nocera and hiscolleagues at MIT can be seen as a special silicon chip with catalysts(催化剂). Similar tonatural leaves, it can splitwater into hydrogen and oxygen when put into a bucket of water. The hydrogenand oxygen gases are then stored in a fuel cell, which usesthose two materials to produce electricity, located eitheron top of a house or beside the house.

Though the leaf is only about the shape of a poker card, scientistsclaimed that it is promising to be an inexpensive source of electricity indeveloping countries.“ One can imagine villages in India and Africa not longfrom now purchasing an affordable basic power system based on this technology, ”said Noceraat a conference of the American Chemical Society.

    The artificial leaf is not a new idea. The first artificial leafwas invented in 1997 but was too expensive and unstable for practical use. Thenew leaf, by contrast, is made ofcheap materials, easy to useand highly stable. In laboratory studies, Nocera showedthat an artificial leaf prototype(原型)could operatecontinuously for at least 45 hours without a drop in activity.

    The wonderful improvements come from Nocera's recent discoveryof several powerful, new andinexpensive catalysts. These catalysts make the energy transformation insidethe leaf more efficient with water and sunlight. Right now, the new leafis about 10 times more efficient at carrying out photosynthesis than a naturalone. Besides, the device canrun in whatever water is available；that is, it doesn'tneed pure water. This is important for some countries that don't have access topure water.

    With the goal to “make each home its own power station” and“give energy to the poor”, scientistsbelieve that the new technology could be widely used in developing countries, especially inIndia and rural China.

    Are some people born clever, and others born stupid? Or is intelligence developed by our environment and our experience? Strangely enough, the answer to these questions is yes. To some degree our intelligence is given to us at birth, and no amount of education can make a genius out of a child born with low intelligence. On the other hand, a child who lives in a boring environment will develop his intelligence less than one who lives in rich and varied surroundings. Thus the limits of person's intelligence are fixed at birth, whether or not he reaches those limits will depend on his environment. This view, now held by most experts, can be supported in a number of ways.

    It is easy to show that intelligence is to some degree something we are born with. The closer the blood relationship between two people, the closer they are likely to be intelligent. Thus if we take two unrelated people at random from population, it is likely that their degree of intelligence will be completely different. If, on the other hand, we take two identical twins, they will very likely be as intelligent as each other. Relations like brothers and sisters, parents and children, usually have similar intelligence, and this clearly suggests that intelligence depends on birth. Imagine now that we take two identical twins and put them in different environments. We might send one, for example, to a university and the other to a factory where the work is boring. We would soon find differences in intelligence developing, and this indicates that environment as well as birth plays a part. This conclusion is also suggested by the fact that people who live in close contact with each other, but who are not related at all are likely to have similar degree of intelligence.

    There lived in South Carolina a young woman named Eliza Lucas. Her father was governor of one of the islands of the West Indies. Miss Lucas often got seeds from her father, and then she planted them in South Carolina.

    Once, her father sent her some seeds of the indigo (靛蓝) plant. She planted some of them in March, but a frost (霜冻) came and killed all her plants. However, she decided to plant some more seeds in April. These grew very well until a cutworm found them and ate her plants. Once more Miss Lucas planted some of the seeds. This time the plants grew very well. She wrote to her father about it. He sent her a man who knew how to get the indigo out of the plant.

    However, the man tried not to show Miss Lucas how to make the indigo. He did not want the people in South Carolina to learn how to make it. He was afraid his own people would not get so much money for their indigo if other people made it as well. So he destroyed the indigo on purpose. But Miss Lucas watched him closely. She worked out how the indigo could be made. Some of her father's land in South Carolina was now planted with the indigo plant.

    Then Miss Lucas got married, and became Mrs. Pinckney. Her father gave her all the indigo growing on his land in South Carolina. It was all saved for seeds. Mrs Pinckney gave some of the seeds to her friends while her husband sowed others. They all grew and were made into the blue dye(染料) that we call indigo. In a few years, South Carolina was producing more than a million pounds of indigo every year. All the people were grateful to her.

    Are you interested in higher education in the United States? The following advice might help you.

    College, University or Institute

    College and universities offer undergraduate degrees in arts and sciences. And both can help prepare young people to earn a living. But many colleges don't offer graduate studies. Universities are generally bigger, offer more programs and do more research. An institute of technology can offer a wide choice of programs and activities. Seventy-five percent of freshmen go there with a strong interest and involvement in the arts.

    The Application Process

    International admissions officers advise students to apply to at least three schools. You may be able to apply online and pay the application charge with a credit card, or by mail. You should study the websites of schools to find information about how and when to apply, how much it will cost and whether any financial aid is available.

    Get a Student Card

    If you request a visa for the first time, you will have to go to an American embassy or consulate(领事馆). You will need to bring a government form sent to you by your American school that shows you have been accepted. A consular official will also take your picture and your fingerprints. You will also need banking and tax records that show you have enough money to pay for your education.

    Financial Aid

    American schools provide aid, like scholarships, fellowships, to almost half of foreign graduate students, but only ten percent of undergraduates. But grants, which, unlike a loan, does not have to be paid.

    I was getting ready to go to bed when the phone rang. This could not be good. My mind raced through the list of family members who might need help, but the voice was hardly familiar.

    "Lindy, this is Lesley." I don't know Lesley well. We did occasionally speak with each other, but to say we were friends was not appropriate. I asked what she needed. Perhaps something really awful caused her to reach someone she barely knew. Instead, she asked me, "Do you have room for a turkey? In your freezer?" We had lots of room in our freezer, and in fact, too much. "Sure," I responded, "did your freezer break down?" "Not exactly," Lesley replied, but I will explain when I arrive."

    Minutes later came a huge freezer truck. Lesley stepped down and explained the lease (租约) of the grocery store her husband serviced had run out and that they had to empty all the freezers that very night. Thinking it was a shame to throw away all this good food, they decided to drop off food to anyone she could think of. Noticing our freezer was pretty empty, Lesley asked to fill it up. Our home was their last stop and anything left would have to be put in our freezer. An hour later, everything finished, I asked her, "When will you come back for all this?" Lesley laughed, "We don't want it back. It is yours! Thanks for helping us out!" Then they waved goodbye and drove away.

    "For helping them out?" We opened our freezer door. Inside were all expensive foods we never bought but often longed to try. We were struggling to buy groceries, yet it was not something we shared with anyone. However, our needs were met in an unexpected way, by that call, "Do you have room for a turkey?"

Tang Dynasty poets sang for about three centuries in different tones. There were many famous poets living in the Tang period, such as Li Bai, Du Fu, Bai Juyi and Li Shangyin. Poems of the Tang Dynasty edited in the Qing Dynasty is a collection of more than 48,900 poems that were written by over 2,200 poets. But it didn't cover all the poems of the Tang Dynasty.

During the Tang Dynasty, poems were recited when lovers walked under the moonlight. Poems were also recited when soldiers fought on the battlefield. People recited them in the open air or at temple fairs.

 Tang Dynasty poets wrote poems to win fame and also to develop their temperament(性情). They poured out deep feelings for their friends and criticised injustice in the society through poems.

 In the Tang Dynasty scholars had to be poets. Their readers were not only people of high social position but also common people. Poets recited poems, women singers sang poems and other ranks of people, including old women and children, read Tang poems. This atmosphere affected foreigners who visited the country at that time. As a result, Tang poetry was introduced to some adjacent countries, like Japan and Vietnam.

 Tang poetry is a most brilliant page in the history of ancient Chinese literature. It's a miracle in the cultural history of mankind. The Tang Dynasty was a powerful empire with a vast territory. It inherited (继承) Chinese civilisation that went back to ancient times, and was combined with the best of other cultures and adopted the benefits of other nations in the world. Tang poetry wasn't the only spiritual wealth created by the Tang Dynasty people. Philosophy and religion, handwriting and painting, and music and dance all gained new peaks of development. Tang poetry, however, was the jewel in the crown and its greatest achievement.