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Every living thing has an inner biological clock that controls behavior. The clock works all the time even when there are no outside signs to mark the passing of time. The biological clock tells plants when to form flowers and when the flowers should open. It tells insects when to leave the protective cocoon and fly away. And it tells animals when to eat, sleep and wake. It controls body temperature, the release of some hormones and even dreams. These natural daily events are circadian rhythms.Man has known about them for thousands of years. But the first scientific observation of circadian rhythms was not made until 1729. In that year French astronomer, Jean-Jac-quesd “Ortous Mairan”, noted that one of his plants opened its leaves at the same time every morning, and closed them at the same time every night. The plant did this even when he kept it in a dark place all the time. Later scientists wondered about circadian rhythms in humans. They learned that man’s biological clock actually keeps time with a day of a little less than 25 hours instead of the 24 hours on a man-made clock. About four years ago an American doctor, Eliot Weitzman, established a laboratory to study how our biological clock works. The people in his experiments are shut off from the outside world. They are free to listen to and live by their circadian rhythms. Dr. Weitzman hopes his research will lead to effective treatments for common sleep problems and sleep disorders caused by aging and mental illness. The laboratory is in the Monteflore Hospital in New York City. It has two living areas with three small rooms in each. The windows are covered, so no sunlight or moonlight comes in. There are no radios or television receivers. There is a control room between the living areas. It contains computers, one-way cameras and other electronic devices for observing the person in the living area. The instruments measure heartbeat, body temperature, hormones in the blood, other substances in the urine and brain waves during sleep. A doctor or medical technician is on duty in the control room 24 hours a day during an experiment. They do not work the same time each day and are not permitted to wear watches, so the person in the laboratory has no idea what time it is. In the first four years of research, Dr. Weitzman and his assistant have observed 16 men between the ages of 21 and 80. The men remained in the laboratory for as long as six months. Last month, a science reporter for The New York Times newspaper, Dava Sobol, became the first woman to take part in the experiment. She entered the laboratory on 13th and stayed for 25 days. Miss Sobol wrote reports about the experiment during that time, which were published in the newspaper.26. The biological clock is believed to play an essential role in ____.27. In his observation, the French scientist noticed that the leaves of a certain plant maintained its opening-and-closing cycles ____.28. The sentence “They are free to listen to and live by their circadian rhythms” (Paragraph 2) probably means ____.29. In the experiment conducted by Mr. Weitzman, the doctor who is on duty does not work the same time each day ____.30. What is Mr. Weitzman’s ultimate purpose of establishing a laboratory?

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The Parthenon, a building in Athens, Greece, is perhaps one of the most Memorable structures on Earth. Built 25 centuries ago, it is one of the great architectural of the ancient world. There are many reasons for its greatness.BackgroundAthens was the most important city in ancient Greece. In 480 B. C. Greece attack by both the Persian army and the Persian navy. The Athenian commander, Themistocles, knew that his forces could not defeat the Persian array then marching toward Athens. Hoping instead to make a stand against the Persians at sea, Themistocles and his forces fled Athens for a nearby island. Although the Persian army overwhelmed Athens and left it in ruins, the Greek navy, led by Themistocles, annihilated the Persian fleet. This victory by the Greeks led all Persian forces to retreat within one year.About 30 years later the building of the Parthenon began. Construction took place between 447 and 432 B.C. During the rule of Pericles, the Parthenon was constructed on the same site as an unfinished structure intended to honor the men who had lost their life in an earlier battle against the Persians. The Parthenon would stand as a symbol of the strength lives and importance of the Greek people.LocationMany important cities in ancient Greece had an acropolis, or “high city”, on which people constructed important buildings. The acropolis was the highest and most defensible location, so it also served as a fortress in the event of enemy attack. The Parthenon is located about 500 feet above the city of Athens. Before the Parthenon could be built, some areas of the acropolis had to be leveled down, and other areas had to be built up. Then a large, solid foundation was constructed out to limestone blocks. The entire area was buttressed by a reinforcing wall.DescriptionThe Parthenon is a rectangular structure consisting of two inner areas surrounded by columns. There are eight columns at each end and seventeen columns along each side. It is a large structure, considering when it was built. It is about 200 feet long and about 100 feet wide. It stands about 60 feet high.ConstructionOne extraordinary aspect of the Parthenon is its construction. It required between 20,000 and 30,000 tons of marble that had to be precisely carved so that huge blocks of it could be fitted together without mortar to form the columns and interior walls.Perhaps even more impressive are the “optical corrections” that were used. The columns bulge slightly in the middle because experience had shown the Greeks that perfectly straight columns would not look straight to viewer. Because comer columns normally smaller than others, the comer columns of the Parthenon were made slightly thicker and were placed closer to the other columns. The columns were also designed to lean inward slightly because perfectly perpendicular columns seem to slant outward. Furthermore the platform on which the Parthenon sits was made to curve upward in the middle because perfectly level floor would appear to sag in the center.The Parthenon stands today despite the fact that the centuries that have passed. It is a timeless tribute to the enduring culture of the Greek people and is considered a model of excellence in concept and construction. It established the classic style of architecture seen today in many public buildings, such as the White House and. the Lincoln Memorial in Washington. D.C. This architectural style is a lasting gift from the ancient Greeks to the modem world.21. The author of the Passage probably views the Parthenon with ____.22. In this passage, the word “annihilated” means ____.23. The passage suggests that most important cities in ancient Greece had an acropolis to ____.24. The reader can conclude that the Parthenon ____.25. What is the approximate length of the Parthenon?

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The argument concerning the use, or the status, or the reality of Black English is rooted in American history and has absolutely nothing to do with the question which the argument supposes itself to be posing. The argument has nothing to do with language itself but with the role of language. Language, incontestably, reveals the speaker. Language, also, far more dubiously, is meant to define the other—and, in this case, the other is refusing to be defined by a language that has never been able to recognize him.People evolve a language in order to describe and thus control their circumstances, or in order not to be submerged by a reality that they cannot articulate. (And, if they cannot articulate it, they are submerged.) A Frenchman living in Paris speaks a subtly and crucially different language from that of the man living in Marseilles; neither sounds very much like a man living in Quebec; and they would all have great difficulty in apprehending what the man from Guadeloupe, or Martinique, is saying, to say nothing of the man from Senegal—although the “common” language of all these areas is French. But each has paid, and is paying, a different price for this “common” language, in which, as it turns out, they are not saying, and cannot be saying, the same things. They each have very different realities to articulate, or control.What joins all languages, and all men, is the necessity to confront life, in order, not inconceivably, to outwit death: The price for this is the acceptance, and achievement, of one’s temporal identity. So that, for example, though it is not taught in the schools the south of France still clings to its ancient and musical Provencal, which resists being described as a “dialect”. And much of the tension in the Basque countries, and in Wales, is due to the Basque and Welsh determination not to allow their languages to be destroyed. This determination also feeds the flames in Ireland, for among the many indignities the Irish have been forced to undergo at English hands is the English contempt for their language.It goes without saying, then, that language is also a political instrument, means, and proof of power. It is the most vivid and crucial key to identity: it reveals the private identity, and connects one with, or divorces one from the larger public, or communal identity. There have been, and are, times and places, when to speak a certain language could be dangerous, even fatal. Or, one may speak the same language, but in such a way that one’s antecedents are revealed, or (one hopes) hidden.1. According to the passage, language reveals the speaker in the way that ____.2. Why does a Frenchman living in Paris has great difficulty in apprehending what the man from Guadeloupe, or Martinique, is saying?3. What does the example of Basque and Welsh illustrate?4. In some places, speaking a certain language may cause ____.5. The text is primarily concerned with discussing ____.

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The climate of Earth is changing. Climatologists are confident that over the past century, the global average surface temperature has increased by about half a degree Celsius. This warming is thought to be at least partly the result of human activities, such as the burning of fossil fuels and the clearing of forests for agriculture. As the global population grows and national economies expand, the global average temperature is expected to continue increasing by an additional 1.0 to 3.5 ℃ by the year 2100.Climate change is one of the most important environmental issues facing humankind. Understanding the potential impacts of climate change for natural ecosystems is essential if we are going to manage our environment to minimize the negative consequences of climate change and maximize the opportunities that it may offer. Because natural ecosystems are complex, nonlinear systems, it follows that their responses to climate change are likely to be complex. Climate change may affect natural ecosystems in a variety of ways. In the short term, climate change can alter the mix of plant species in land ecosystems such as grasslands. In the long term, climate change has the potential to dramatically alter the geographic distribution of major vegetation types—savannas, forests, and tundra. Climate change can also potentially alter global ecosystem processes, including the cycling of carbon, nitrogen, phosphorus, and sulfur. Moreover, changes in these ecosystem processes can affect and be affected by changes in the plant species of the ecosystem and vegetation type. All of the climate—change induced alterations of natural ecosystem services that these ecosystems provide to humans.The global average surface temperature increase of half a degree Celsius observed over the past century has been in part due to differential changes in daily maximum and minimum temperatures, resulting in a narrowing of the diurnal temperature range. Decreases in the diurnal temperature range were first identified in the United States, where large-area trends showed that maximum temperatures have remained constant or increased only slightly, whereas minimum temperatures have increased at a faster rate. In this issue, Alward et al. report on the different sensitivities of rangeland plants to minimum temperatures increases.11. Which of the following is NOT mentioned as a reason for the global warming?12. The second paragraph is primarily concerned with ____.13. According to the author, what may chiefly be responsible for the temperature increases observed over the past century?14. In subsequent paragraphs, we may expect the writer of this passage to ____.15. The word “diurnal” (Paragraph 3) is closest in meaning to “____”.

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