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Practice 5 The world's oceans are slowly getting more acidic, say scientists. The researchers from California say the change is taking place in response to higher levels of carbon dioxide in the atmosphere. The lowering of the waters' pH value is not great at the moment but could pose a serious threat to current marine life if it continues, they warn. Ken Caldeira and Michael Wickett, from the Lawrence Livermore National Laboratory, report their concerns in the journal Nature. Increasing use of fossil fuels means more carbon dioxide is going into the air, and most of it will eventually be absorbed by seawater. Once in the water, it reacts to form carbonic acid. Scientists believe that the oceans have already become slightly more acidic over the last century. But these researchers have tried to predict what will happen in the future by combining what we know about the history of the oceans with computer models of climate change. "This level of acidity will get much more extreme in the future if we continue releasing CO2 into the atmosphere," said Dr Caldeira. "And we predicted amounts of future acidity that exceed anything we saw over the last several hundred million years, apart from perhaps after rare catastrophic events such as asteroid impacts." If carbon dioxide release continues unabated, ocean pH could be reduced by as much as 0.77 units, the authors warn. It is not absolutely clear what that means for marine life, however. Most organisms live near the surface, where the greatest pH change would be expected to occur, but deep-ocean lifeforms may be more sensitive to pH changes. Coral reefs and other organisms whose skeletons or shells contain calcium carbonate may be particularly affected, the team speculate. They could find it much more difficult to build these structures in water with a lower pH. In recent years some people have suggested deliberately storing carbon dioxide from power stations in the deep ocean as a way of curbing global warming. But Dr Caldeira said that such a strategy should now be re-considered. "Previously, most experts had looked at ocean absorption of carbon dioxide as a good thing — because in releasing CO2 into the atmosphere we warm the planet; and when CO2 is absorbed by the ocean, it reduces the amount of greenhouse warming.
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更多 “问答题Practice 5 The world's oceans are slowly getting more acidic, say scientists. The researchers from California say the change is taking place in response to higher levels of carbon dioxide in the atmosphere. The lowering of the waters' pH value is not great at the moment but could pose a serious threat to current marine life if it continues, they warn. Ken Caldeira and Michael Wickett, from the Lawrence Livermore National Laboratory, report their concerns in the journal Nature. Increasing use of fossil fuels means more carbon dioxide is going into the air, and most of it will eventually be absorbed by seawater. Once in the water, it reacts to form carbonic acid. Scientists believe that the oceans have already become slightly more acidic over the last century. But these researchers have tried to predict what will happen in the future by combining what we know about the history of the oceans with computer models of climate change. "This level of acidity will get much more extreme in the future if we continue releasing CO2 into the atmosphere," said Dr Caldeira. "And we predicted amounts of future acidity that exceed anything we saw over the last several hundred million years, apart from perhaps after rare catastrophic events such as asteroid impacts." If carbon dioxide release continues unabated, ocean pH could be reduced by as much as 0.77 units, the authors warn. It is not absolutely clear what that means for marine life, however. Most organisms live near the surface, where the greatest pH change would be expected to occur, but deep-ocean lifeforms may be more sensitive to pH changes. Coral reefs and other organisms whose skeletons or shells contain calcium carbonate may be particularly affected, the team speculate. They could find it much more difficult to build these structures in water with a lower pH. In recent years some people have suggested deliberately storing carbon dioxide from power stations in the deep ocean as a way of curbing global warming. But Dr Caldeira said that such a strategy should now be re-considered. "Previously, most experts had looked at ocean absorption of carbon dioxide as a good thing — because in releasing CO2 into the atmosphere we warm the planet; and when CO2 is absorbed by the ocean, it reduces the amount of greenhouse warming.” 相关考题
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You will have to practice () times before you can do it .
A.may moreB.more severalC.more oftenD.more many
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– The radio announcer says the storm is getting nearer. –()Well.
(A) it’s not to my taste(B) it’s too sunny(C) just take his statement with a pinch of salt(D) the more, the better
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We think it necessary to prevent sound ( ), as it is getting more and more serious.
A、conditionB、inventionC、pollutionD、position
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It' s getting dark. I'm afraid I must be off now.OK.()A. Take it easy.B. Go slowly.C. See you.
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This district is getting more and more ________ and bustling。
A.prosperousB.amateurC.favoriteD.annual
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Many source of information can _____ our chances of getting in touch with the current event in the world.AexpendBimagineClimitDenhance
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The political situation is steadily () in that country. More and more people are getting involved in the dispute.
A、decreasingB、decliningC、breaking upD、worsening
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【T1】A.SEEKB.LOOKEDC.PART A.TAKING【T1】______IN DANGEROUS SPORTS AND ACTIVITIESB.WHO HAVE【T2】______FOR ADVENTUREC.WHO【T3】______AN IMMEDIATE EXCITEMENT FROM A RISKY ACTIVITY AROUND THE WORLD MORE AND MORE PEOPLE ARE【T4】______.OF COURSE, THERE HAVE ALWAYS BEEN PEOPLE【T5】______—THOSE WHO HAVE CLIMBED THE HIGHEST MOUNTAINS, EXPLORED UNKNOWN PARTS OF THE WORLD OR SAILED IN SMALL BOATS ACROSS THE GREATEST OCEANS.NOW, HOWEVER, THERE ARE PEOPLE【T6】_______ WHICH MAY ONLY LAST A FEW MINUTES OR EVEN SECONDS.
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【T5】A.SEEKB.LOOKEDC.PART A.TAKING【T1】______IN DANGEROUS SPORTS AND ACTIVITIESB.WHO HAVE【T2】______FOR ADVENTUREC.WHO【T3】______AN IMMEDIATE EXCITEMENT FROM A RISKY ACTIVITY AROUND THE WORLD MORE AND MORE PEOPLE ARE【T4】______.OF COURSE, THERE HAVE ALWAYS BEEN PEOPLE【T5】______—THOSE WHO HAVE CLIMBED THE HIGHEST MOUNTAINS, EXPLORED UNKNOWN PARTS OF THE WORLD OR SAILED IN SMALL BOATS ACROSS THE GREATEST OCEANS.NOW, HOWEVER, THERE ARE PEOPLE【T6】_______ WHICH MAY ONLY LAST A FEW MINUTES OR EVEN SECONDS.
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How does the writer feel about the business she runs? ( )A．It's the biggest company in the world．B．It wili possibly be more successful．C． It's one of the most successful businesses．D．It is the only company that is growing all around the world．
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What is a cause for the change of Stefania’s body clock?A．Eating fewer hours of sleep.B．Having more hours of sleepC．Lacking physical exercise.D．Getting no natural light.
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How does the writer feel about the business she runs?A. It's the biggest company in the world.
B. It will possibly be more successful.
C. It's one of the most successful businesses.
D. It is the only company that is growing all around the world.
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资料：Large industrialized are now in a recession. What are the prospects for economic recovery?
The three most important industrial economies in the world are, at the moment, facing enormous problems. Germany is struggling with the cost of reunification and is in recession. Japan is also experiencing recession and the United States has a large budget deficit.
Forecasters and analysts face questions about the prospects of an economic recovery. Here are some of their findings:
The election of a new president of the United States gave hope to the rest of the world. If the US recovered, the rest of the world would face a more promising future. However, analysts now accept that the US will only recover very slowly.
Consumer and investor confidence is still lacking. Large deficits and declining short-term interest rates mean there is little scope for economic stimulus.
The Japanese economy, after years of trade and budget surpluses, is in deep recession and the growth rate has slowed down considerably. German economists have lowered their forecasts for economic growth this year. The lowering of German interest rates may bring some relief to other members of the European Exchange Rate Mechanism （ERM）. However, Germany's importance as Europe's largest export market may decline.
However, in some parts of the world, there are more positive signs, particularly in some Latin American countries in South-East Asia. Analysts says that, as long as the rate of interest stays above the rate of growth at national income, then the ratio of debt to income will get worse. Falling interest rates help towards overcoming this problem. They believe it may take several years before there is real recovery. However, advances in technology are offering hope for the world economy.
According to the passage, which one is NOT true?
A.Consumer and investor still hold confidence in the US economy.
B.There is little scope for provoking the economy.
C.US is predicted to be recovering very slowly.
D.The US recovery would give the rest of the world a more promising future.
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共用题干
Traffic Jams一No End in Sight1 Traffic congestion（拥堵）affects people throughout the world. Traffic jams cause smog in dozens of cities across both the developed and developing world. In the U. S.,commuters（通勤人员）spend an average of a full working week each year sitting in traffic jams,according to the Texas Transportation Institu-te.While alternative ways of getting around are available,most people still choose their cars because they are looking for convenience,comfort and privacy.2 The most promising technique for reducing city traffic is called congestion pricing,whereby cities charge a toll to enter certain parts of town at certain times of day.In theory,if the toll is high enough,some drivers will cancel their trips or go by bus or train.And in practice it seems to work:Singapore,London and Stockholm have reduced traffic and pollution in city centres thanks to congestion pricing.3 Another way to reduce rush-hour traffic is for employers to implement flexitime,which lets employees travel to and from work at off-peak traffic times to avoid the rush hour. Those who have to travel during busy times can do their part by sharing cars.Employers can also allow more staff to telecommute(work from home)so as to keep more cars off the road altogether.4 Some urban planners still believe that the best way to ease traffic congestion is to build more roads, especially roads that can take drivers around or over crowded city streets.But such techniques do not really keep cars off the road;they only accommodate more of them.5 Other,more forward-thinking,planners know that more and more drivers and cars are taking to the roads every day,and they are unwilling to encourage more private automobiles when public transport is so much better both for people and the environment.For this reason,the American government has decided to spend some$7 billion on helping to increase capacity on public-transport systems and upgrade them with more efficient technologies.But environmentalists complain that such funding is tiny compared with the$50 billion being spent on roads and bridges.The U.S.government has planned to_________updating public-transport systems.A:go by busB:encourage more private carsC:drive aroundD:spend more moneyE:reduce traffic jamsF:travel regularly
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The would“it”in the last sentence refers to_______.A.seawater
B.purified water
C.the process of getting rid of the salt in seawater
D.the process of collecting salt from the sea oceans
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An administrator is getting reports that a file server is responding slowly. Which of the following steps should the administrator take FIRST？（）A、Remove unnecessary files on the server to free up hard disk space.B、Defragment the server’s hard disks.C、Compare monitoring results with the server baseline.D、Add additional memory to reduce paging.
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问答题Practice 5 Never has there been a language quite like English. A bold statement, yet nevertheless true. Consider a few statistics. Today, one out of every seven people in the world use English in some way. More than half the world’s books are written in English; the majority of international telephone calls are made in English; 60% of the world’s radio programs are broadcast in English. English is even the working language of international air travel. For the first time in history, a single language has become dominant across a wide range of human activity, ranging from music, film and fine arts to the fields of business, diplomacy, science and technology.
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单选题As for Wal-Mart itself, it can be inferred that______.A
there are 5,200 stores all over the world.B
Wal-Mart has more than 7,000 trucks over the world.C
Wal-Mart has great influence on world market.D
Lee Scott is Wal-Mart’s CEO and decision-maker.
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问答题Practice 4 Few creations of big technology capture the imagination like giant dams. Perhaps it is humankind’s long suffering at the mercy of flood and drought that makes the ideal of forcing the waters to do our bidding so fascinating. But to be fascinated is also, sometimes, to be blind. Several giant dam projects threaten to do more harm than good. The lesson from dams is that big is not always beautiful. It doesn’t help that building a big, powerful dam has become a symbol of achievement for nations and people striving to assert themselves. Egypt’s leadership in the Arab world was cemented by the Aswan High Dam. Turkey’s bid for First World status includes the giant Ataturk Dam.
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问答题Practice 1 The catchphrase of the hour is that America is living beyond its means. The expression is used so much by politicians, economists and editorial writers that it is depreciating faster than the dollar. But there's no way around it. It tells the story. The Data Resources numbers show Americans increase their spending this year almost three times as fast as their after-tax income. What else can we explain it? What is more, as a nation, the U.S. has been doing the same thing throughout the 1990s. For years the country has been consuming more than it produces, making up the difference by borrowing abroad. It can't go on. The stock market's tumble, which has caused a loss of $1 trillion in paper wealth, is but the first step in a process that must sober the nation. At the same time, in the next few years the U. S. will have to throw its amazing dream machine into reverse and start paying its debts. Inevitably, this will mean a lowering in the U.S. standard of living as Americans are forced to produce more than they consume to service a soaring foreign debt. Per capital income may keep rising but more slowly than in the past. The trade account will go slowly towards balance or even surplus in the mid-1990s. But in the meantime, Americans will receive less for their exports because the dollar will fall considerably before U. S. exports are competitive. And pressures to reduce the federal deficit will tighten the lid on defense spending.
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问答题Globalization is making the world smaller, faster and richer. Still, 9/11 and avian flu remind us that a smaller, faster world is not necessarily a safer world. Our world is bursting with knowledge—but desperately in need of wisdom. Now, when sound bites are getting shorter, when instant messages crowd out essays, and when individual lives grow more crazy, college graduates capable of deep reflection are what our world needs.
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问答题Practice 10 The momentum is building ahead of next month’s G8 summit in Scotland where the leaders of the world’s richest nations will debate what they can do to help some of the world’s poorest. Africa is the priority and the politicians will discuss reducing the debt burden, ending trade regulations which put the continent’s economy at a disadvantage, and giving more aid. Mark Doyle, who’s reported from Africa for many years, looks at why aid is necessary, and why much of what’s been donated in the past has not worked. All around the edge of Africa-along the coastline, near the continents’ ports—are monuments to exploitation. On the island of Goree, for example, just off the coast of Senegal, there’s: the Slave House. This was the last place many Africans saw before being shipped off to a lifetime of slavery in American or, just as often, to death on the high seas. There are many more places like this dating from the three hundred and fifty years or so of the African slave trade. When people wonder why Africa is so poor, they need look no further for the start of an explanation.
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问答题Practice 3 Energy-saving vehicles were part of the Green Transportation Festival in the US in 2003. The vehicles shown were designed to reduce America’s dependence on oil and help the environment. There are exhibits of cars and buses at the festivals. Most of them use little gas or use another kind of fuel such as natural gas. People are also urged to consider simpler ways of getting around, such as walking, biking and using public transportation systems. The United States has less than five per cent of the world’s population, but uses about twenty-five per cent of the world’s oil. More than half of the nation’s oil is imported. Most of it goes to transportation. Festival organizers said progress in technology was making it possible for Americans to reduce their dependence on oil. That is because the kinds of energy-saving vehicles are increasing. Efforts to reduce oil imports in the United States would also have important environmental benefits. The burning of oil as fuel is responsible for gases blamed for climate change. When gasoline is burned in cars, it also pollutes the air. This leads to many health problems.
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单选题A
Helping some of the world’s poorest.B
Reducing the debt burden of Africa.C
Giving more aid to Africa.D
Building democracies and fighting corruption.
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单选题Looming over the debate about human interference in the world’s boreal forests is an as yet unanswerable question: Will the effects of global warming eventually dwarf man’s impact?A
raise to greater importanceB
make more difficult to measureC
cause to appear smallD
bring to an abrupt end
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