2.Climate and the Collapse of Maya Civilization
2023年高考英语外刊时文精读专题05气候变化零碳排放(含答案)
高考英语外刊时文精读专题：2023年高考英语外刊时文精读精练 (5)Climate change气候变化Heat island热岛主题语境：人与自然主题语境内容：人与环境【外刊原文】（斜体单词为超纲词汇，认识即可；下划线单词为课标词汇，需熟记。
）On March 13th, as commuters（每日往返上班者）streamed out of Chhatrapati Shivaji Terminus,a gothic revival masterpiece（哥特式复兴建筑——贾特拉帕蒂·希瓦吉终点站）in Mumbai, India’s commercial capital, they were confronted with temperatures approaching40°C, nearly7°C above normal for the time of year. The city is in the midst of a debilitating heatwave, its 13th in the past five decades, nearly half of which occurred in the past 15 years. Mumbai’s average temperature has increased by over 1°C in that period.Had those commuters crossed the street from the station and entered the city’s grand headquarters that day, they might have found cause for optimism. That afternoon politicians from the authority and the state of Maharashtra, of which Mumbai is the capital, had gathered to unveil（揭露）a “climate action plan”. The city aims to reach net-zero emissions by 2050, two decades earlier than the target set by the national government.Mumbai is extremely vulnerable to climate change.A narrow and densely populated（人口密集的）island, surrounded on three sides by the Arabian Sea, it is attacked by monsoon(季候风) rains for four months a year and routinely subject to flooding, especially during high tide. That is bad enough for thecity’s apartment-dwellers（公寓居民）. But it is even worse for the 42% of the population who live in slums（贫民窟）, which are likely to be washed away or buried by landslides（山体滑坡）.The key of the plan is a proposal to decarbonise（去碳化）Mumbai’s energy. Generating the city’s electricity, which produces nearly two-thirds of the city’s emissions, relies mostly on burning fossil fuels, particularly coal. The city wants to increase the share of renewables （可再生资源）. It is looking, for instanceinto installing solar panels（装太阳能电池板）on rooftops.Another priority is to improve the quality andefficiency of the city’s buildings.Slums, especially, are heat islands. Made of whatever materials are at hand or cheaply available, they are five or six degrees hotter than structures of good quality, making them, as the report puts it, “uninhabitable(不适于居住的)” on hot days. Moreover, the heat, damp and cramped(狭窄的)conditions make slum residents more vulnerable to disease—a less obvious risk of climate change.The plan is, however, short on details of how to achieve its ambition s. Still, in publishing one at all Mumbai has led the way among South Asian metropolises(大都市). Other cities are keen to follow suit, says Shruti Narayan of C40, who helped with the report. Chennai and Bangalore in the south have started work on their plans. Others, including Delhi and Kolkata in India, Dhaka in Bangladesh and Karachi in Pakistan have expressed interest in doing something similar.There is plenty in Mumbai’s240-page document to inspire them. One is the fact that it does not rely on using technologies that do not yet exist, a criticism at many countries’ national proposals. Another is the attention given to adaptation(coping with all the bad things already happening) and not just reducing future emissions.Details may anyway be beside the point. The real value of Mumbai’s plan is as a signalling device(信号装置)that “focuses the attention of policymakers”, states Abhas Jha, a climate specialist at the World Bank. The Paris Agreement, which committed the world to the goal of keeping the rise in temperatures to less than 2°C above pre-industrial levels, worked in much the same way, leaving countries to hash out details later. Time, though, is getting ever shorter.【课标词汇】1.stream（一群人，东西）涌，涌动；流动He was watching the taxis streaming past.他看着出租车一辆接着一辆地驶过。
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托福备考托福阅读34套TPO样题+解析+译文14--2 Maya Water Problems
托福考试 复习托福阅读TPO14(试题+答案+译文)第2篇:Maya Water Problems托福阅读原文【1】To understand the ancientMayan people who lived in the area that is today southern Mexico and CentralAmerica and the ecological difficulties they faced, one must first considertheir environment, which we think of as "jungle" or "tropicalrainforest." This view is inaccurate, and the reason proves to beimportant. Properly speaking, tropical rainforests grow in high-rainfall equatorialareas that remain wet or humid all year round. But the Maya homeland lies morethan sixteen hundred kilometers from the equator, at latitudes 17 to 22 degreesnorth, in a habitat termed a "seasonal tropical forest." That is,while there does tend to be a rainy season from May to October, there is also adry season from January through April. If one focuses on the wet months, onecalls the Maya homeland a "seasonal tropical forest"; if one focuseson the dry months, one could instead describe it as a "seasonaldesert".【2】From north to south in theYucatan Peninsula, where the Maya lived, rainfall ranges from 18 to 100 inches(457 to 2,540 millimeters) per year, and the soils become thicker, so that thesouthern peninsula wasagriculturally more productive and supported denserpopulations. But rainfall in the Maya homeland is unpredictably variablebetween years; some recent years have had three or four times more rain thanother years. As a result, modern farmers attempting to grow corn in the ancientMaya homelands have faced frequent crop failures, especially in the north. Theancient Maya were presumably more experienced and did better, but neverthelessthey too must have faced risks of crop failures from droughts and hurricanes.【3】Although southern Maya areasreceived more rainfall than northern areas, problems of water wereparadoxically more severe in the wet south. While that made things hard forancient Maya living in the south, it has also made things hard for modernarchaeologists who have difficulty understanding why ancient droughts causedbigger problems in the wet south than in the dry north. The likely explanationis that an area of underground freshwater underlies the Yucatan Peninsula, butsurface elevation increases from north to south, so that as one moves south theland surface lies increasingly higher above the water table. In the northernpeninsula the elevation is sufficiently low that the ancient Maya were able toreach the water table at deep sinkholes called cenotes, or at deep caves. Inlow-elevation north coastal areas without sinkholes, the Maya would have beenable to get down to the water table by diggingwells up to 75 feet (22 meters)deep. But much of the south lies too high above the water table for cenotes orwells to reach down to it. Making matters worse, most of the Yucatan Peninsulaconsists of karst, a porous sponge-like limestone terrain where rain runsstraight into the ground and where little or no surface water remainsavailable.【4】How did those dense southernMaya populations deal with the resulting water problem? It initially surprisesus that many of their cities were not built next to the rivers but instead onhigh terrain in rolling uplands. The explanation is that the Maya excavateddepressions, or modified natural depressions, and then plugged up leaks in thekarst by plastering the bottoms of the depressions in order to createreservoirs, which collected rain from large plastered catchment basins andstored it for use in the dry season. For example, reservoirs at the Maya cityof Tikal held enough water to meet the drinking water needs of about 10,000people for a period of 18 months. At the city of Coba the Maya built dikesaround a lake in order to raise its level and make their water supply morereliable. But the inhabitants of Tikal and other cities dependent on reservoirsfor drinking water would still have been in deep trouble if 18 months passedwithout rain in a prolonged drought. A shorter drought in which they exhaustedtheir stored food supplies might already have gotten them in deep trouble,because growing cropsrequired rain rather than reservoirs.托福阅读试题1.Why does the author call the Mayan homeland both a “seasonal tropical forest” and “seasonal desert”(Paragraph 1)?A.To illustrate how the climate of the Mayan homeland varied from region to region.B.To explain how the climate of the Mayan homeland is similar to that of a jungle or tropical rainforest.C.To emphasize the vast size of the area that comprised the Mayan homeland in ancient times.D.To make the point that the Mayan homeland is climatically more complex than is generally assumed.2.Which of the following is NOT mentioned in paragraph 2 as a difference between the northern and southern Yucatan Peninsula?A.The annual rainfall was greater in the south.B.The population density was lower in the north.C.Agricultural productivity was greater in the south.D.Rainfall was more unpredictable and variable in the south.3.Which of the following statements about ancient and modem agriculture in the Yucatan Peninsula is supported by paragraph 2?A.Modern agricultural methods have solved many of the ancient problems of farming in the Yucatan Peninsula.B.Ancient Mayan farmers may have been somewhat more successful at farming in the Yucatan Peninsula than farmers are today.C.Farming today is easier than in the past because environmental changes in the Yucatan Peninsula have increased available rainfall.D.The Yucatan soils in which ancient farmers worked were richer, more productive, and thicker than they are today.4.The wo rd “paradoxically”(Paragraph 3)in the passage is closest in meaning toually.B.surprisingly.C.understandably.D.predictably.5.The phrase “The likely explanation”(Paragraph 3)in the passage refers to the explanation for whyA. the southern Maya areas received more rainfall than the northern areas.B. modern archaeologists have difficulty understanding ancient droughts.C. water problems were most severe in the wet south.nd surface in the south is so high above the water table.6.Which of the following statements about the availability of water in the Mayan homeland is supported by paragraph 3?A.The construction of wells was an uncommon practice in both the north and the south because it was too difficult to dig through the karst.B.In most areas in the north and the south, rainwater was absorbed directly into the porous karst.C.The water table was an important resource for agriculture in both the north and the south of the Yucatan Peninsula.D.The lack of surface water in both the north and the south was probably due to the fact that most of it was quickly used up for agricultural purposes.7.According to paragraph 3, why was the southern Mayan homeland hard to farm?A.The presence of numerous sinkholes and wells interfered with farming.B.Southern soil lacked the depth crops needed for growth.C.Underground water was too far below the surface to reach.D.The presence of karst caused frequent flooding.8.Which of the sentences below best expresses the essential information in the highlighted sentence(paragraph 4) in the passage? Incorrect choices change the meaning in important ways or leave out essential information.A.Southern Maya populations obtained the water they needed for the dry season by collecting and storing rainwater in sealed depressions.B.The Maya are credited with creating methods for modifying naturalrainwater and storing it.C.Leaks in the karst caused difficulties in the creation of reservoirs, which were needed to store water for the dry season.D.Southern Mayans were more successful at collecting rain than storing it during dry seasons.9.What can be inferred from paragraph 4 about how residents of Tikal met their needs for water and food during most periods of drought? A.They depended upon water and food that had been stored for use during the dry season.B.They obtained drinking water and water for crop irrigation from Coba dikes.C.They located their population centers near a lake where water was available for drinking and watering crops.D.They moved locations every 18 months to find new croplands and water sources.10.The word "prolonged" in the passage(paragraph 4)is closest in meaning toA.unusual.B.unexpected.C.extended.D.disastrous.11.The word "exhausted" in the passage(paragraph 4)is closest inmeaning toed up.B.reduced.C.wasted.D.relied upon.12. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit? The difference between the two climates challenged the Maya who had to deal with both.To understand the ancient Mayan people who lived in the area that is today southern Mexico and Central America and the ecological difficulties they faced, one must first consider their environment, which we think of as "jungle" or "tropical rainforest." ■【A】This view is inaccurate, and the reason proves to be important. ■【B】Properly speaking, tropical rainforests grow in high-rainfall equatorial areas that remain wet or humid all year round. But the Maya homeland lies more than sixteen hundred kilometers from the equator, at latitudes 17 to 22 degrees north, in a habitat termed a "seasonal tropical forest." ■【C】That is, while there does tend to be a rainy season from May to October, there is also a dry season from January through April. If one focuses on the wet months, one calls the Maya homeland a "seasonal tropical forest"; if one focuses on the dry months, one could instead describe it as a "seasonal desert."■【D】13.Directions: Select from the seven phrases below the phrases that correctly characterize the southern Mayan homeland and the phrases that correctly characterize the northern Mayan homeland. Drag each phrase you select into the appropriate column of the table. Two of the phrases will NOT be used. This question is worth 3 points.A. City of Tikal.B. Predictable rainfall.C. High above water table.D. Used reservoirs.E. Obtained water from wells.F.Dramatically improved corn crops.G. Had comparatively thin layer of soil.1 ）Southern Mayan homelandA B C D E F G2 ）Northern Mayan homelandA B C D E F G托福阅读答案1.修辞目的题，修辞点所在的句子只是单纯在说一个例子，所以往前看，前句说有雨季也有旱季，所以对应的是答案D，MAYA地区的气候复杂多变。
莱昂纳多在联合国气候峰会的演讲中英对照
莱昂纳多在联合国气候峰会的演讲Thank you, Mr. Secretary General, for the honor to address this body once more. And thanks to the distinguished climate leaders assembled here today who are ready to take action.谢谢秘书长先生再次给我机会让我站在这里发言，谢谢各位卓越的气候领导人今天在联合国大会汇聚一堂准备开始采取行动。
body：团体；组织President Abraham Lincoln was also thinking of bold action 150 years ago when he said: “The dogmas of the quiet past are inadequate to the stormy present…As our case is new, so we must think anew and act anew. We must disenthrall ourselves, and then we shall save our country.”150年前，亚伯拉罕·林肯总统也曾考虑过采取大胆的行动，他说：“那些属于宁静往日的教条已不足以应付风雨飘摇的现在，由于我们面临新的问题，我们要有新的思维、新的行动，我们必须打破自身的枷锁，才能拯救我们的国家。
”dogma ['dɒgmə] ：教条，教理disenthrall [,disin'θrɔ:l]：释放；解放He was speaking before the U.S. Congress to confront the defining issue of his time – slavery. Everyone knew it had to end, but no one had the political will to stop it. Remarkably, his words ring as true today when applied to the defining crisis of our time – climate change.当时林肯总统在美国国会发表了这席演讲，正视他的时代所面临的关键问题——奴隶制。
《The Consequences of Climate Change》高考优秀英语作文
《The Consequences of Climate Change》高考优秀英语作文The Consequences of Climate ChangeClimate change is one of the most pressing issues facing our planet today. Not only is it a global issue, but it affects every living creature on Earth, and its impact is becoming increasingly serious.The consequences of climate change are far-reaching and can be seen through physical, economic and social changes. Examples of physical changes include rising sea levels, land degradation, more frequent and intense droughts, floods, hurricanes and other extreme weather events. These extreme events have caused severe damage to natural ecosystems, resulting in declines in wildlife populations and reduced availability of fresh water for humans.The economic consequences of climate change include higher costs for food production and distribution, increased energy prices, and the loss of coastal property and tourism. Higher temperatures also mean a decrease in manufacturing productivity, thus leading to a further negative effect on economies.The social implications of climate change have caused displacement of people from their homelands due to extreme weather events, as well as food insecurity and poverty. Other associated risks include health impacts as a result of air pollution and water-related diseases, and mental health issues such as stress and anxiety.Given these facts, it is clear that climate change is an urgent issue that must be addressed. We must take action both locally andglobally to reduce greenhouse gas emissions and promote sustainable development. By doing so, we can help to protect our planet for future generations.。
The Impact of Climate Change on Agriculture
The Impact of Climate Change onAgricultureClimate change has become one of the most pressing issues of our time, withfar-reaching implications for various aspects of our lives, including agriculture. The impact of climate change on agriculture is significant and multifaceted, affecting crop yields, water availability, and the overall productivity of farming systems. As global temperatures continue to rise and weather patterns become more unpredictable, farmers are facing new challenges that threaten their livelihoods and food security. One of the most immediate and visible effects of climate change on agriculture is the alteration of growing seasons and crop cycles. Warmer temperatures and shifting weather patterns can disrupt the traditional plantingand harvesting schedules that farmers rely on. This can lead to decreased crop yields, as crops may not have enough time to mature properly or may be exposed to extreme weather events such as droughts or floods. In some regions, farmers are being forced to adapt by changing the types of crops they grow or investing in new technologies to mitigate the effects of climate change. Another major concern for farmers is the availability of water for irrigation. Climate change is causing changes in precipitation patterns, leading to more frequent and severe droughts in some areas and increased rainfall in others. This variability in wateravailability can make it difficult for farmers to plan and manage their irrigation systems effectively. In many regions, water scarcity is becoming a critical issue, with farmers facing tough decisions about how to allocate limited water resources among competing demands. In addition to changes in growing seasons and water availability, climate change is also contributing to the spread of pests and diseases that can devastate crops. Warmer temperatures and altered weatherpatterns create favorable conditions for pests to thrive and spread to new regions. This can lead to significant crop losses and increased use of pesticides, whichcan have negative environmental and health impacts. Farmers are having to invest more time and resources in pest management strategies to protect their crops and maintain their yields. The impact of climate change on agriculture is not just limited to crop production; it also affects livestock farming and food security.Rising temperatures can stress animals and reduce their productivity, leading to lower meat and dairy yields. Changes in precipitation patterns can also affect the availability of feed and water for livestock, further impacting their health and well-being. In some regions, farmers are being forced to reduce their livestock numbers or switch to more resilient breeds in order to adapt to changing environmental conditions. Overall, the impact of climate change on agriculture is a complex and evolving challenge that requires urgent action at the global, national, and local levels. Farmers need support and resources to help them adapt to changing conditions and build resilience in the face of climate change. This includes access to information and technologies that can help them make informed decisions about crop management, water use, and pest control. Governments and policymakers also have a role to play in implementing policies and incentives that promote sustainable farming practices and reduce greenhouse gas emissions. In conclusion, the impact of climate change on agriculture is a critical issue that requires immediate attention and action. Farmers are on the front lines of this challenge, facing new and unprecedented threats to their livelihoods and food security. By working together to address the root causes of climate change and support farmers in adapting to changing conditions, we can help ensure a sustainable future for agriculture and food production.。
(生物)高中英语阅读理解《人与自然相处》及答案
（生物）高中英语阅读理解《人与自然相处》及答案物竞天择，适者生存，物种的起源与进化经历了自然界亿万年的沧海桑田。
而在所有已知的生命体中，人类，因其无限的创造力，无疑是最伟大的。
他们也曾对自然充满敬畏之心，直到科学技术为他们掀开了自然界的神秘面纱。
人类开始改造自然，向自然索取，以滋养其不断扩张的人口。
这是人类的福音，却是自然和其他物种的灾难。
阅读题目，回答问题（说明文，全文473词。
摘自China Daily）One million of the planet’s eight million species are threatened with extinction by humans,scientists warned on Monday in what is described as the most comprehensive assessment of global nature loss ever.Their landmark report paints a picture of a planet damaged by anever-growing human population,whose insatiable（贪得无厌的）consumption is destroying the natural world.The global rate of species extinction“is already tens to hundreds of times higher than it has been,on average,over the last10million years”, according to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services(IPBES),a UN committee,whose report was written by145experts from50countries.Shrinking habitat,exploitation of natural resources,climate change and pollution are the main drivers of species loss and are threatening more than40%of amphibians,33%of coral reefs and over a third of all marine mammals with extinction,the IPBES report said.“The health of ecosystems on which we and all other species dependis deteriorating more rapidly than ever,”said Sir Robert Watson,IPBES chair,adding that“transformative change”is needed to save the planet. The report comes six months after the UN Intergovernmental Panel on Climate Change(IPCC)warned that the world has less than12years to avoid catastrophic levels of global warming.Just as with climate change,humans are the main culpritsof biodiversity damage,changing75%of Earth’s land and66%of marine ecosystems since pre-industrial times,according to the report.The report emphasizes the disastrous impact of population growth and rising demand.It notes that the world’s population has more than doubled (from3.7to7.6billion)in the last50years,and gross domestic product per person is four times higher.More than a third of the world’s land and75%of freshwater supplies are used for crop or livestock production,it noted.“There is very little of the planet left that has not been significantly changed by us,”Sandra Diaz,co-author of the report and professor of ecology at the University of Córdoba,told CNN.“We need to act as stewards for life on Earth.”Diaz said countries in the Global North are particularly to blame for nature damage due to their“unsustainable”levels of consumption,especially when it comes to fishing and logging.Despite the ominous picture“it is not too late to make a difference,but only if we start now at every level from local to global,”said Watson, adding that this would require an overhaul of economic systems and a shift in social mindsets.1.The“picture”painted in the report is.A.promisingB.attractiveC.misleadingD.depressing2.What does theunderlined word“deteriorating”in Paragraph5 probably mean?A.ImprovingB.DecreasingC.WorseningD.Working3.What can we inferfrom Diaz’s opinion?A.Fishing and farming make a big damage tonature.B.Population growth results in lack of landand water.C.Economic systems have been made a shiftglobally.D.Human’s increasing consumption leads tonature damage.4.What is the author’s purpose in writing the passage?A.To showways of protecting species.B.Toexplain the consequences of global warming.C.Tointroduce the report written by IPBES.D.To urgepeople to start to protect the earth.参考答案D C D D生词与长难句1.insatiable adj.不知足的；无法满足的insatiable curiosity永不满足的好奇心2.coral reef珊瑚礁3.marine mammals海洋哺乳动物4.The report comes sixmonths after the UN Intergovernmental Panel on Climate Change(IPCC)warnedthat the world has less than12years to avoid catastrophic levels of globalwarming.句子主干：The report comes.句子翻译：联合国政府间气候变化专门委员会警告说世界只剩下不到12年的时间来避免灾难性的全球变暖，6个月后，该项报告就出台了。
2023年高考英语外刊时文精读专题14气候变化与珊瑚礁
2023年高考英语外刊时文精读精练 (14)Climate change and coral reefs气候变化与珊瑚礁主题语境：人与自然 主题语境内容：自然生态【外刊原文】（斜体单词为超纲词汇，认识即可；下划线单词为课标词汇，需熟记。
）Human beings have been altering habitats—sometimes deliberately andsometimes accidentally—at least since the end of the last Ice Age.Now, though,that change is happening on a grand scale. Global warming is a growing factor.Fortunately,the human wisdom that is destroying nature can also be brought to bear on trying to save it.Some interventions to save ecosystems are hard to imagine andsucceed. Consider a project to reintroducesomething similar to a mammoth(猛犸象) to Siberiaby gene-editing Asian elephants. Their feeding habits could restore the grassland habitat that was around before mammoths died out, increasing the sunlight reflected into space and helping keep carbon compounds (碳化合物) trapped in the soil. But other projects have a bigger chance of making an impact quickly. As we report, one example involves coral reefs.These are the rainforests of the ocean. They exist on vast scales: half a trillion corals line the Pacific from Indonesia to French Polynesia, roughly the same as the number of trees that fill the Amazon.They are equally important harbor of biodiversity. Rainforests cover 18%of the land’s surface and offer a home to more than half its vertebrate(脊椎动物的) species. Reefs occupy 0.1%of the oceans and host a quarter of marine(海洋的) species.And corals are useful to people, too. Without the protection which reefs afford from crashing waves, low-lying islands such as the Maldives would have flooded long ago, and a billion people would lose food or income. One team of economists has estimated that coral’s global ecosystem services are worth up to $10trn a year. reefs are, however, under threat from rising sea temperatures. Heat causes the algae（海藻） with which corals co-exist, and on which they depend for food and colour,to generate toxins（毒素）that lead to those algae’s expulsion（排出）.This is known as“bleaching（白化）”, and can cause a coral’s death.As temperatures continue to rise, research groups around the world are coming up with plansof action. Their ideas include identifying naturally heat-resistant（耐热的）corals and moving themaround the world; crossbreeding（杂交）such corals to create strains that are yet-moreheat-resistant; employing genetic editing to add heat resistance artificially; transplantingheat-resistant symbiotic （共生的）algae; and even repairing with the bacteria and other micro-organismswith which corals co-exist—to see if that will help.The assisted evolution of corals does not meet with universal enthusiasm.Without carbon reduction and decline in coral-killing pollution, even resistant corals will not survive the century. Some doubt whetherhumans will get its act together in time to make much difference. Few of these techniques are ready for action in the wild. Some, such as gene editing, are so controversia l that it is doubtful they will be approved any time soon. scale is also an issue.But there are grounds for optimism.Carbon targets are being set and ocean pollution is being dealt with.Countries that share responsibilities for reefs are starting to act together. Scientific methods can also be found. Natural currents can be used to facilitate mass breeding. Sites of the greatest ecological and economical importance can be identified to maximise benefits.This mix of natural activity and human intervention could serve as a blueprint（蓝图） for other ecosystems. Those who think that all habitats should be kept original may not approve.But when entire ecosystems are facing destruction, the cost of doing nothing is too great to bear. For coral reefs, at least, if any are to survive at all, it will be those that humans have re-engineered to handle the future.【课标词汇精讲】1.alter （通常指轻微地）改动，修改；改变，（使）变化We've had to alter some of our plans.我们不得不对一些计划作出改动。
(生物)高中英语阅读理解《人与自然相处》及答案
（生物）高中英语阅读理解《人与自然相处》及答案物竞天择，适者生存，物种的起源与进化经历了自然界亿万年的沧海桑田。
而在所有已知的生命体中，人类，因其无限的创造力，无疑是最伟大的。
他们也曾对自然充满敬畏之心，直到科学技术为他们掀开了自然界的神秘面纱。
人类开始改造自然，向自然索取，以滋养其不断扩张的人口。
这是人类的福音，却是自然和其他物种的灾难。
阅读题目，回答问题（说明文，全文473词。
摘自China Daily）One million of the planet’s eight million species are threatened with extinction by humans,scientists warned on Monday in what is described as the most comprehensive assessment of global nature loss ever.Their landmark report paints a picture of a planet damaged by anever-growing human population,whose insatiable（贪得无厌的）consumption is destroying the natural world.The global rate of species extinction“is already tens to hundreds of times higher than it has been,on average,over the last10million years”, according to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services(IPBES),a UN committee,whose report was written by145experts from50countries.Shrinking habitat,exploitation of natural resources,climate change and pollution are the main drivers of species loss and are threatening more than40%of amphibians,33%of coral reefs and over a third of all marine mammals with extinction,the IPBES report said.“The health of ecosystems on which we and all other species dependis deteriorating more rapidly than ever,”said Sir Robert Watson,IPBES chair,adding that“transformative change”is needed to save the planet. The report comes six months after the UN Intergovernmental Panel on Climate Change(IPCC)warned that the world has less than12years to avoid catastrophic levels of global warming.Just as with climate change,humans are the main culpritsof biodiversity damage,changing75%of Earth’s land and66%of marine ecosystems since pre-industrial times,according to the report.The report emphasizes the disastrous impact of population growth and rising demand.It notes that the world’s population has more than doubled (from3.7to7.6billion)in the last50years,and gross domestic product per person is four times higher.More than a third of the world’s land and75%of freshwater supplies are used for crop or livestock production,it noted.“There is very little of the planet left that has not been significantly changed by us,”Sandra Diaz,co-author of the report and professor of ecology at the University of Córdoba,told CNN.“We need to act as stewards for life on Earth.”Diaz said countries in the Global North are particularly to blame for nature damage due to their“unsustainable”levels of consumption,especially when it comes to fishing and logging.Despite the ominous picture“it is not too late to make a difference,but only if we start now at every level from local to global,”said Watson, adding that this would require an overhaul of economic systems and a shift in social mindsets.1.The“picture”painted in the report is.A.promisingB.attractiveC.misleadingD.depressing2.What does theunderlined word“deteriorating”in Paragraph5 probably mean?A.ImprovingB.DecreasingC.WorseningD.Working3.What can we inferfrom Diaz’s opinion?A.Fishing and farming make a big damage tonature.B.Population growth results in lack of landand water.C.Economic systems have been made a shiftglobally.D.Human’s increasing consumption leads tonature damage.4.What is the author’s purpose in writing the passage?A.To showways of protecting species.B.Toexplain the consequences of global warming.C.Tointroduce the report written by IPBES.D.To urgepeople to start to protect the earth.参考答案D C D D生词与长难句1.insatiable adj.不知足的；无法满足的insatiable curiosity永不满足的好奇心2.coral reef珊瑚礁3.marine mammals海洋哺乳动物4.The report comes sixmonths after the UN Intergovernmental Panel on Climate Change(IPCC)warnedthat the world has less than12years to avoid catastrophic levels of globalwarming.句子主干：The report comes.句子翻译：联合国政府间气候变化专门委员会警告说世界只剩下不到12年的时间来避免灾难性的全球变暖，6个月后，该项报告就出台了。
The Impact of Climate Change(雅思阅读)
The Impact of Climate Change on Global Biodiversity气候变化对全球生物多样性的影响Climate change is a pressing global issue that is having significant impacts on ecosystems and biodiversity around the world. In recent years, rising global temperatures, changing precipitation patterns, and extreme weather events have altered natural habitats and disrupted the delicate balance of ecosystems.气候变化是一个紧迫的全球问题，对世界各地的生态系统和生物多样性产生了重大影响。
近年来，全球气温上升、降水模式变化和极端天气事件已经改变了自然栖息地，并破坏了生态系统的微妙平衡。
One of the primary impacts of climate change on biodiversity is the loss of habitats and species extinction. As temperatures rise, many species are forced to migrate to higher altitudes or latitudes to find suitable conditions for survival. This migration disrupts food chains and can lead to the disappearance of certain species that are unable to adapt quickly enough.气候变化对生物多样性的主要影响之一是栖息地丧失和物种灭绝。
TPO-19 Reading 2翻译
SUCCESSION, CLIMAX, AND ECOSYSTEMS演替、顶级群落与生态系统In the late nineteenth century, ecology began to grow into an independent science from its roots in natural history and plant geography. The emphasis of this new "community ecology" was on the composition and structure of communities consisting of different species. In the early twentieth century, the American ecologist Frederic Clements pointed out that a succession of plant communities would develop after a disturbance such as a volcanic eruption, heavy flood, or forest fire. An abandoned field, for instance, will be invaded successively by herbaceous plants (plants with little or no woody tissue), shrubs, and trees, eventually becoming a forest. Light-loving species are always among the first invaders, while shade-tolerant species appear later in the succession.在19世纪末期，生态学开始从它的源头——自然历史学和植物地理学中脱离出来成为一门独立的学科。
全国卷2025届高考英语2月高分模拟卷卷7含解析
（全国卷）2025届高考英语2月高分模拟卷（卷7）（含解析）(时间：120分钟满分：120分)选择题部分第一部分阅读理解(共两节，满分50分)第一节(共15小题；每小题2.5分，满分37.5分)阅读下列短文，从每题所给的四个选项A、B、C和D中，选出最佳选项。
A（2024·河北衡水市·衡水中学高三月考）The Apollo Missions“That's one small step for a man. One giant leap for mankind.”—Neil Armstrong Apollo’s GoalsThe national effort that enabled Astronaut Neil Armstrong to speak those words as he stepped onto the lunar surface fulfilled a dream as old as humanity. Project Apollo’s goals went beyond landing Americans on the moon and returning them safely to Earth.Apollo 13Apollo 13 has been called a “successful failure,” because the crew never landed on the Moon, but they made it home safely after an explosion crippled their ship. When the associated heater was turned on during flight, the tankexploded depleting almost all of the power from the command module and forcing the crew to use the lunar module as a lifeboat. Jim Lovell, Fred Haise and Jack Swigert came home safely thanks to the mission control team’s improvised procedures and their own ability to implement them.(Launch: April 11, 1970; splashdown: April 17)Apollo 14Notable for the return of America’s first astronaut, Alan Shepard, to space, Apollo 14 also was probably the smoothest lunar landing to that point. The crew spent more than nine hours outside the lunar module and set up a number of experiments. Shepard set a new distance record by walking more than 9,000 feet on the lunar surface, pulling a hand cart to carry their tools and samples.(Launch: Jan. 31, 1971: lunar landing: Feb. 5: splashdown, Feb. 9) Apollo 15For the first time, humans drove a car on the Moon. The first of the Apollo “J” Missions-designed for longer stays on the Moon - the mission carried a lunar rover, which Commander David Scott and Lunar Module Pilot James Irwin used while they were on the surface for more than I8 hours. They traveled more than 17 miles in the rover, setting up experiments and collecting 170 pounds of samples. Before leaving the lunar surface, Scott conducted an experiment to test Galileo’s theory that objects in vacuum, without air resistance, would fall at the same rate. He dropped a geological hammer and a feather, which hit the ground at the same time, proving Galileo right.(Launch: July 26, 1971, lunar landing: July 30: splashdown: Aug. 7)1．Why has Apollo 13 been called a “successful failure”?A．Apollo 13 finally exploded as planned in space.B．All the crew succeeded in landing on the Moon.C．The crew managed to escape from a severe accident and returned to Earth. D．The crew finished the experiment although they failed to land on the Moon. 2．Which of the following is True according to the passage?A．It took five days for Apollo 14 to reach the Moon.B．The lunar rover was used as a lifeboat for space travel.C．Shepard tested Gali leo’s theory successfully on the Moon.D．Apollo 15 remained in space for the shortest period of time.3．Which of the following column is this article most likely to be found? A．Booming Science B．Exploring the Unknown C．Mechanical World D．Transforming MoonB（2024·黑龙江哈尔滨市第六中学校高三期末）Staying connectedWhen Central Bucks South became one of the first Philadelphia-area high schools to close because of the fear of novel coronavirus exposure in early March, 16-year-old sophomore Andrew Chen knew that things were not going to return to normal as quickly as some of his peers hoped.But still, the change from seeing his friends on the swim team during daily practices to learning alone at home was jarring.“I only have three years her e at South, and it pains me to see one of them being wasted,” Chen said.The coronavirus has changed everyone’s lives, but for students, the disruption feels particularly serious. Schools closed and graduation ceremonies were put off. Summer plans, such as camps, are up in the air.But right now, many students are trying to stay connected, struggling with false information, and finding out the best ways they can help –through online method.For Josh Harycki, 17, a senior student at the Shipley School in Philadelphia, the best way to help was to create a “social distancing promise” for young people.“I saw a lot of young people not paying attention,” he said. “They were … still going out, hanging out with others. I thought that there had to be a way to reach younger people, who were possibly not watching the news.”Harycki started a call to action on social media and then built a website with a map that followed and kept the locations of people who’d signed the promise. The site also shares links to accurate sources of information like the US Centers for Disease Control and Prevention.Harycki knows that his peers are worried they can’t connected with their friends in the same way, so he created the social distancing promise to strengthen that although everyon e might be physically distant, they’re still connected.“Part of what we’re showing is that you might feel like you’re the only one taking this seriously, but our map shows that you’re not alone,” he said. 4．What does the underlined word “jarring” in Parag raph 2 probably mean? A．naturalB．necessaryC．worryingD．reasonable5．Who does Harycki mainly want to reach?A．Friends who are worried and bored.B．Young people not aware of the situation.C．Younger students trying to help.D．People taking the coronavirus seriously.6．What’s Harycki’s purpose in creating the “social distancing promise”? A．To order young people to stay at home.B．To follow those infected with the coronavirus.C．To tell young folks of latest news about the coronavirus.D．To show young people that they are still connected.7．Why does the author describe Andrew Chen’s experience in the text?A．To explain what worried students most when schools closed.B．To show the different views of students toward the coronavirus.C．To show how the coronavirus affected students’ lives.D．To explain the proper reaction to the close of school.C（2024·全国高三专题练习） One night in 1966, Michael Chapman rushed into a folk-music club in Cornwall, England to get out of the rain, and soon found himself onstage playing the guitar.“They offered me a job to play for the rest of the summer. And I’ve been playing ever since,” Chapman says. “I’ve told that story so many times, but it’s absolutely true. If it hadn’t been raining that night, I wouldn’t be talking to you.”The British guitar player has spent the 50 years since then on the road. He released some praised albums in the 1970s, but his health went downhill in the 80s and 90s. Like a lot of British artists in the 1960s, Chapman taught himself to play the guitar by listening to American jazz and blues records.Chapman actually taught photography, but quit when he was 26 to play music full time. When he was starting out, he was often compared to other British acoustic guitar heroes of the time, like John Martyn and Bert Jansch.“The fascinating thing about Michael Chapman is that he doesn’t fit in with those guys of his generation,” says Andrew Male, a music journalist. “He’s always been an outsider. He never moved to London. ”And while he never became part of the London music scene, Chapman was noticed by those musicians. “The 70s caught up with him in the 80s,” Male says. “He had a huge heart attack at the end of the 80s that nearly finished him off. When he made his way back into the world in the early 90s, people had forgotten about him.” But not everyone. A younger generation of musicians in America, including Thurston Moore of Sonic Youth and a younger singer and guitarist named Steve Gunn, recently rediscovered Chapman.“We wanted to capture Michael’s voice and character where he is now. You know, it’s a little road-weary, but he still has it,” Gunn says. “For me, it was really important to get that right.” “He’s the right old musician for present times,” Male says. “I think the music he makes seems quite in tune with where we’re at.”8．Which can best describe Michael Chapman’s first involvement in music? A．Untrue. B．Accidental. C．Unfortunate. D．Reasonable. 9．What can we learn about Michael Chapman from the text?A．He has taught photography for 26 years.B．He taught himself to play the guitar and did far better than John Martyn. C．To some degree, he is not accepted by other people of his generation. D．He is one of the best guitar players in the early 90s.10．Why did Michael Chapman quit his music career once?A．He lost his special voice. B．He suffered from a severe heart attack.C．He got tired of competing with others. D．He was almost forgotten by everyone.11．Which of the following can be the best title for the text?A．The Rise and Fall of Guitar Music B．The Sad Story of a Guitar Musician C．A New Generation Helps an Old Guitar Musician D．A Brief Introduction to a Guitar MusicianD（2024·天水市第一中学高三月考） How many times a day do you check your email? When you wake up? Before bed? A dozen limes in between? The technology that was supposed to make our lives simple has taken up too much time. The average teen spends more than seven hours a day using technological devices, with an additional hour just text-messaging friends.The advantage of technological devices is connectedness. Email lets us respond on the go, and we are in touch with more people during more hours of the day than at any other time in history. But is it possible that we’re lonelier than ever, too? That’s what MIT professor Sherry Turkle observes in her new book, Alone Together, which clearly describes our changing relationship with technology.For Turkic, the biggest worry is the effect the weak connections have on our development. T echnology isn’t offering us the lives we want to live. “We’re texting people at a distance” says Turkic. “We’re using lifelessobjects to convince ourselves that even when we’re alone, we feel together. And then when we’re with each other, we put ourselves in situations where we are alone—always on our mobile devices. It’s what I call a perfect storm of confusion about what’s important in our human connections.”Moreover, communicating online is not equal to face-to-face communication. Online, you can ignor e others’ feelings. In a text message, you can avoid eye contact A number of studies have found that this generation of young people is sympathetic (有怜悯心的) than ever. “That doesn’t lead to disaster,” says Turkle, “but the disadvantages still cannot be ignored.”12．From the first paragraph we can learn that .A．Email checking helps people wake up earlyB．People communicate mainly by text-messaging nowC．Technological device production has been simplifiedD．Using technological devices costs young men much time13．What is Sherry Turkic’s biggest worry?A．Technology may make human connections confusing.B．Technology can’t help people remove loneliness.C．Technology may make people’s lives hard.D．Technology keeps people together.14．What is the author’s at titude towards the influence of technology on people’s life?A．Positive B．NegativeC．Hopeless D．Uncertain15．What is the passage mainly about?A．Technology brings many conveniences to people’s lives.B．Young men spend too much time on technological devices.C．Technology also brings people some disadvantages.D．Sherry Turkle observes people’s changing relationship with Technology.其次节(共5小题；每小题2.5分，满分12.5分)依据短文内容，从短文后的选项中选出能填入空白处的最佳选项。
托福最新阅读真题及参考答案
The Collapse of the MayaThe Mayan society of Central America (2000 B.C-A.D 1500), like other ancient states, was characterized by populations unprecedented both in their size and density. It was not just the number of people that lived in the Mayan city-states but also the relatively small area into which they were concentrated. To support such populations, societies developed various intensive agricultural including large-scale irrigation and hill-slope (the cutting of horizontal ridges into hillsides so they can be farmed). These were designed both to increase yields from a given area and to increase the absolute amount of land under cultivation. These strategies were in essence very successful: they made it possible to feed larger populations than ever before and supported the growth of cites. But they also placed considerable strains on the environment and rendered it increasingly fragile and vulnerable to unexpected climatic events, and even to short-term fluctuations. Thus, the argument is that because of their size and ever more intensive agriculture, the Mayan and other ancient state societies were fundamentally unsustainable.Claims about environment degradation and disaster have figured prominently in discussion of the collapse of the Mayan city-states of the Central American lowlands. When two explorers came upon the Mayan cities in the 1830s, they were struck by the sight of tall pyramids and elaborately carved stones among luxuriant forest growth. Here was the archetypal picture of a great lost civilization: abandoned cities submerged in vegetation. Theories of catastrophic collapse or apocalyptic overthrow came naturally to mind to explain these dramatic scenes.Recent studies of the Mayan collapse (beginning around A.D 900) have emphasized the gradual and progressive nature of the process, beginning in the earliest in the South and advancing northward. It was not a single, sudden event, as had once been thought. Warfare and social unrest are thought to have played a part, but these may well have arisen through pressure from other causes. The Mayan cities had, after all, flourished for over 500 years and had frequently been at war with each other.But what about the possibility of food shortages? These could have come about through either natural or humanly induced changes in the environment. Increasingly fierce competition between Mayan cities led to an upsurge of monument construction during the eighth and ninth centuries A.D, which would have placed added strain on agricultural production and expansion. Interstaterivalry may hence have pushed the Maya toward overexploitation of their fragile ecosystem. Deforestation and soil erosion might ultimately have destroyed the capacity of the land to support the high population levels of the Mayan cities, leading to famine, social unrest, and the collapse of the major Mayan centers.Yet it may be incorrect to lay the blame entirely on human action. Several of the lowland cities, such as Tikal, appear to have depended heavily on the cultivation of raised fields set in the marshy depressions known as bajos, which today flood intermittently in the rainy season but may originally have been permanent lakes. The raise-field system of intensive cultivation (created by digging surrounding canals and using the soil removed to elevate the fields for planting) allows year-round food production through the constant supply of soil nutrients that erode into the drainage ditches dug around the raised fields, nutrients that are then collected and replaced. Stable water levels were essential to this subsistence system, but evidence from Lake Chichancanab in Yucatan shows that between A.D 800 and A.D 1000 this region suffered its driest period of climate in several thousand years. We may expect that as a result water level fell, and the raised fields in many areas became unusable. But the human response must be viewed through the lens of the social, political, and cultural circumstances. These exerted a powerful mediating effect on the way the Maya endeavored to cope with their difficulties. Had population levels been lower, the impact of the drought may not have been catastrophic, as it was, the Maya were already reaching the limits of the available subsistence capacity, and Mayan elites had espoused certain social and political agendas (including expensive warfare and competition with each other). It was against this specific background that a period of drought led quickly to crisis and collapse.Paragraph 1The Mayan society of Central America (2000 B.C-A.D 1500), like other ancient states, was characterized by populations unprecedented both in their size and density. It was not just the number of people that lived in the Mayan city-states but also the relatively small area into which they were concentrated. To support such populations, societies developed various intensive agricultural including large-scale irrigation and hill-slope (the cutting of horizontal ridges into hillsides so they can be farmed). These were designed both to increase yields from a given area and to increase the absolute amount of land under cultivation. Thesestrategies were in essence very successful: they made it possible to feed larger populations than ever before and supported the growth of cites. But they also placed considerable strains on the environment and rendered it increasingly fragile and vulnerable to unexpected climatic events, and even to short-term fluctuations. Thus, the argument is that because of their size and ever more intensive agriculture, the Mayan and other ancient state societies were fundamentally unsustainable.1.According to paragraph 1, ancient societies increased their agricultural output byA. increasing the percentage of the population that worked as farmersB. creating large irrigation systemsC. being highly selective of the fields they would farmD. moving more people into the city to free up farmland2.Which of the following can be inferred from paragraph 1 about the intensive agricultural methods of the Maya?A. They helped the Maya overcome shot-term fluctuations in the climate.B. They could not supply all of the food required for the growth of Mayan cities.C. They strained the environment more than the Maya’s previous farmingtechniques did.D. They were invented by the Maya to help them grow new kinds of crops. Paragraph2Claims about environment degradation and disaster have figured prominently in discussion of the collapse of the Mayan city-states of the Central American lowlands. When two explorers came upon the Mayan cities in the 1830s, they were struck by the sight of tall pyramids and elaborately carved stones among luxuriant forest growth. Here was the archetypal picture of a great lost civilization: abandoned cities submerged in vegetation. Theories of catastrophic collapse or apocalyptic overthrow came naturally to mind to explain these dramatic scenes.3.The word “elaborately” in the passage is closest in meaning toA. with great detailB. artisticallyC. mysteriouslyD. gently hand-made4.The word “abandoned” in the passage is closest in meaning toA. carefully hiddenB. destroyedC. enormousD. no longer occupied5.In paragraph 2, the author implies which of the following about the collapse of the Mayan city-states?A. The fact that vegetation had grow over the ruins of Mayan buildings indicatesthat environmental degradation did not contribute to the Mayan collapse.B. Early explorers supposed that there was a catastrophic collapse of the Mayancity states largely because this view fit their preconceived ideas about lost civilizations.C. The condition of the tall pyramids and carved stones discovered by earlyexplorers proves that Mayan city-states were violently overthrown.D. The Mayan cities were abandoned because they became submerged invegetationParagraph 3Recent studies of the Mayan collapse (beginning around A.D 900) have emphasized the gradual and progressive nature of the process, beginning in the earliest in the South and advancing northward. It was not a single, sudden event, as had once been thought. Warfare and social unrest are thought to have played a part, but these may well have arisen through pressure from other causes. The Mayan cities had, after all, flourished for over 500years and had frequently been at war with each other.6.Why does the author include the information that Mayan cities had “flourished for over 500 years and had frequently been at war with each other”?A. To identify a possible reason for the eventual collapse of Mayan societyB. To make the point that war and social unrest alone do not account for theMayan collapseC. To explain why recent studies argue that human actions were responsible forthe Mayan collapseD. To provide evidence that frequent wars weakened Mayan society only verygradually7.According to paragraph 3, recent studies claim which of the following about the Mayan collapse?A. It was caused primarily by frequent wars between rival city-states.B. It was caused by a single sudden event.C. It was preceded by social unrest in northern city-states.D. It began in southern city-states and spread to others.Paragraph 4But what about the possibility of food shortage? These could have come about through either natural or humanly induced changes in the environment. Increasingly fierce competition between Mayan cities led to an upsurge of monument construction during the eighth and ninth centuries A.D, which would have placed added strain on agricultural production and expansion. Interstate rivalry may hence have pushed the Maya toward overexploitation oftheir fragile ecosystem. Deforestation and soil erosion might ultimately have destroyed the capacity of the land to support the high population levels of the Mayan cities, leading to famine, social unrest, and the collapse of the major Mayan centers.8.All of the following are mentioned in paragraph 4 as possible direct or indirect caused of food shortages EXCEPTA. increased monument constructionB. rivalries between statesC. deforestation and stationD. introduction of new cropsParagraph 5Yet it may be incorrect to lay the blame entirely on human action. Several of the lowland cities, such as Tikal, appear to have depended heavily on the cultivation of raised fields set in the marshy depressions known as bajos, which today flood intermittently in the rainy season but may originally have been permanent lakes. The raise-field system of intensive cultivation (created by digging surrounding canals and using the soil removed to elevate the fields for planting) allows year-round food production through the constant supply of soil nutrients that erode into the drainage ditches dug around the raised fields, nutrients that are then collected and replaced. Stable water levels were essential to this subsistence system, but evidence from Lake Chichancanab in Yucatan shows that betweenA.D 800 and A.D 1000 this region suffered its driest period of climate in several thousand years. We may expect that as a result water level fell, and the raised fields in many areas became unusable. But the human response must be viewed through the lens of the social, political, and cultural circumstances. These exerted a powerful mediating effect on the way the Maya endeavored to cope with their difficulties. Had population levels been lower, the impact of the drought may not have been catastrophic, as it was, the Maya were already reaching the limits of the available subsistence capacity, and Mayan elites had espoused certain social and political agendas (including expensive warfare and competition with each other). It was against this specific background that a period of drought led quickly to crisis and collapse.9.The word “entirely” in the passage is closest in meaning toA. generallyB. clearlyC. completelyD. specifically10.The word “intermittently” in the passage is closest in meaning toA. constantlyB. periodicallyC. usuallyD. especially11.According to paragraph 5, why did the raised fields in many areas become unusable?A. The marshy depressions around the fields flooded in the rainy seasonB. Intensive cultivation of the fields drained the soil of nutrients.C. The area where the fields were located experienced a drop in water levels.D. Unstable design caused the failure of the drainage ditches.12.According to paragraph 5, all of the following made it more difficult for the Maya to cope with effects of the drought EXCEPTA. failure to properly cultivate the fieldsB. high population levelsC. competition between Mayan groupsD. warfareParagraph 5Yet it may be incorrect to lay the blame entirely on human action. 【A】Several of the lowland cities, such as Tikal, appear to have depended heavily on the cultivation of raised fields set in the marshy depressions known as bajos, which today flood intermittently in the rainy season but may originally have been permanent lakes. 【B】The raise-field system of intensive cultivation (created by digging surrounding canals and using the soil removed to elevate the fields for planting) allows year-round food production through the constant supply of soil nutrients that erode into the drainage ditches dug around the raised fields, nutrients that are then collected and replaced. 【C】Stable water levels were essential to this subsistence system, but evidence from Lake Chichancanab in Yucatan shows that between A.D 800 and A.D 1000 this region suffered its driest period of climate in several thousand years. 【D】We may expect that as a result water level fell, and the raised fields in many areas became unusable. But the human response must be viewed through the lens of the social, political, and cultural circumstances. These exerted a powerful mediating effect on the way the Maya endeavored to cope with their difficulties. Had population levels been lower, the impact of the drought may not have been catastrophic, as it was, the Maya were already reaching the limits of the available subsistence capacity, and Mayan elites had espoused certain social and political agendas (including expensive warfare and competition with each other). It was against this specific background that a period of drought led quickly to crisis and collapse.13.Look at the four squares [■] that indicate where the following sentence could be added to the passage.Nature apparently also contributed to the food shortages.Where would the sentence best fit?14.Directions：An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.Since the discovery of the Mayan ruins in the 1830s, researchers have tried to explain the collapse of Mayan civilization.Answer choicesA. The Mayan attempt to develop intensive agricultural methods to support largepopulations in relatively small areas probably was unsuccessful and couldhave caused the Mayan collapse.B. The discovery of intact pyramids submerged in vegetation among the Mayanruins led researchers to believe that Mayan cities were simply overgrownrather than catastrophically destroyed.C. Warfare and rivalry between Mayan states may have caused food shortagesthat contributed to the eventual collapse of Mayan civilization.D. Early theories that the Mayan collapse was a sudden, catastrophic event werefollowed by views that treated the collapse as a gradual process.E. The continuing warfare and social unrest that started in the North and spreadto the South provided researchers with evidence that the Mayan collapse tookhundreds of years to occur.F. Drought between A. D. 800 and A.D. 1000 likely caused the Mayan system ofintensive irrigated agriculture to fall, which could have brought about a rapidcollapse of the Mayan states.参考答案：BCADB BDDCB CAA CDF。
climate change no eden no apocalypse 课文
climate change no eden no apocalypse 课文Climate change is a natural phenomenon that has been occurring on Earth for millions of years. It is driven by various factors, including changes in the Earth's orbit, volcanic activity, and fluctuations in solar radiation. However, human activities have greatly accelerated the pace of climate change in recent decades.Contrary to some beliefs, climate change is not a sudden catastrophe that will lead to an apocalyptic scenario. It is a gradual process that has already had noticeable effects on the planet. These effects include rising global temperatures, melting ice caps and glaciers, and more frequent and intense extreme weather events.It is important to note that climate change is also not a return to an Eden-like paradise. While some regions may experience more favorable conditions, overall, climate change poses significant challenges and risks. The changing climate disrupts ecosystems, threatens biodiversity, and leads to the loss of habitats for many species. It also affects human societies, particularly vulnerable communities in developing countries, by exacerbating poverty, food insecurity, and water scarcity.Addressing climate change requires a collective effort from individuals, governments, and industries worldwide. This involves reducing greenhouse gas emissions, transitioning to clean and renewable energy sources, and adapting to the changes that are already occurring. It also includes taking measures to protect vulnerable communities and ecosystems from the impacts of climate change.By acknowledging the reality of climate change and taking proactive measures to mitigate its effects, we can create a more sustainable and resilient future for ourselves and future generations.。
托福阅读真题第140篇TheCollapseoftheMaya（答案文章最后）
托福阅读真题第140篇TheCollapseoftheMaya（答案文章最后）The Mayan society of Central America (2000 B.C-A.D 1500), like other ancient states, was characterized by populations unprecedented both in their size and density. It was not just the number of people that lived in the Mayan city-states but also the relatively small area into which they were concentrated. To support such populations, societies developed various intensive agricultural including large-scale irrigation and hill-slope (the cutting of horizontal ridges into hillsides so they can be farmed). These were designed both to increase yields from a given area and to increase the absolute amount of land under cultivation. These strategies were in essence very successful: they made it possible to feed larger populations than ever before and supported the growth of cites. But they also placed considerable strains on the environment and rendered it increasingly fragile and vulnerable to unexpected climatic events, and even to short-term fluctuations. Thus, the argument is that because of their size and ever more intensive agriculture, the Mayan and other ancient state societies were fundamentally unsustainable.Claims about environment degradation and disaster have figured prominently in discussion of the collapse of the Mayan city-states of the Central American lowlands. When two explorers came upon the Mayan cities in the 1830s, they were struck by the sight of tall pyramids and elaborately carved stones among luxuriant forest growth. Here was the archetypal picture of a great lost civilization: abandoned cities submerged in vegetation. Theories of catastrophic collapse or apocalyptic overthrow came naturally to mind to explain these dramatic scenes.Recent studies of the Mayan collapse (beginning around A.D 900) have emphasized the gradual and progressive nature of the process, beginning in the earliest in the South and advancing northward. It was not a single, sudden event, as had once been thought. Warfare and social unrest are thought to have played a part, but these may well have arisen through pressure from other causes. The Mayan cities had, after all, flourished for over 500 years and had frequently been at war with each other.But what about the possibility of food shortage? These could have come about through either natural or humanly induced changes in the environment. Increasingly fierce competition between Mayan cities led to an upsurge of monument construction during the eighth and ninth centuries A.D, which would have placed added strain on agricultural production and expansion. Interstate rivalry may hence have pushed the Maya toward overexploitation of their fragile ecosystem. Deforestation and soil erosion might ultimately have destroyed the capacity of the land to support the high population levels of the Mayan cities, leading to famine, social unrest, and the collapse of the major Mayan centers.Yet it may be incorrect to lay the blame entirely on human action. Several of the lowland cities, such as Tikal, appear to have depended heavily on the cultivation of raised fields set in the marshy depressions known as bajos, which today flood intermittently in the rainy season but may originally have been permanent lakes. The raise-field system of intensive cultivation (created by digging surrounding canals and using the soil removed to elevate the fields for planting) allows year-round food production through the constant supply of soil nutrients that erode into the drainage ditches dug around the raised fields,nutrients that are then collected and replaced. Stable water levels were essential to this subsistence system, but evidence from Lake Chichancanab in Yucatan shows that between A.D 800 and A.D 1000 this region suffered its driest period of climate in several thousand years. We may expect that as a result water level fell, and the raised fields in many areas became unusable. But the human response must be viewed through the lens of the social, political, and cultural circumstances. These exerted a powerful mediating effect on the way the Maya endeavored to cope with their difficulties. Had population levels been lower, the impact of the drought may not have been catastrophic, as it was, the Maya were already reaching the limits of the available subsistence capacity, and Mayan elites had espoused certain social and political agendas (including expensive warfare and competition with each other). It was against this specific background that a period of drought led quickly to crisis and collapse.【Paragraph 1】The Mayan society of Central America (2000 B.C-A.D 1500), like other ancient states, was characterized by populations unprecedented both in their size and density. It was not just the number of people that lived in the Mayan city-states but also the relatively small area into which they were concentrated. To support such populations, societies developed various intensive agricultural including large-scale irrigation and hill-slope (the cutting of horizontal ridges into hillsides so they can be farmed). These were designed both to increase yields from a given area and to increase the absolute amount of land under cultivation. These strategies were in essence very successful: they made it possible to feed larger populations than ever before and supported the growth of cites. But they also placed considerable strains on the environment and rendered it increasingly fragileand vulnerable to unexpected climatic events, and even to short-term fluctuations. Thus, the argument is that because of their size and ever more intensive agriculture, the Mayan and other ancient state societies were fundamentally unsustainable.1. Which of the following can be inferred from paragraph 1 about the intensive agricultural methods of the Maya?A. They helped the Maya overcome shot-term fluctuations in the climate.B. They could not supply all of the food required for the growth of Mayan cities.C. They strained the environment more than the Maya’s previous farming techniques did.D. They were invented by the Maya to help them grow new kinds of crops.【Paragraph 2】Claims about environment degradation and disaster have figured prominently in discussion of the collapse of the Mayan city-states of the Central American lowlands. When two explorers came upon the Mayan cities in the 1830s, they were struck by the sight of tall pyramids and elaborately carved stones among luxuriant forest growth. Here was the archetypal picture of a great lost civilization: abandoned cities submerged in vegetation. Theories of catastrophic collapse or apocalyptic overthrow came naturally to mind to explain these dramatic scenes.2. In paragraph 2, the author implies which of the following about the collapse of the Mayan city-states?A. The fact that vegetation had grown over the ruins of Mayan buildings indicates that environmental degradation did not contribute to the Mayan collapse.B. Early explorers supposed that there was a catastrophiccollapse of the Mayan city states largely because this view fit their preconceived ideas about lost civilizations.C. The condition of the tall pyramids and carved stones discovered by early explorers proves that Mayan city-states were violently overthrown.D. The Mayan cities were abandoned because they became submerged in vegetation.【Paragraph 3】Recent studies of the Mayan collapse (beginning around A.D 900) have emphasized the gradual and progressive nature of the process, beginning in the earliest in the South and advancing northward. It was not a single, sudden event, as had once been thought. Warfare and social unrest are thought to have played a part, but these may well have arisen through pressure from other causes. The Mayan cities had, after all, flourished for over 500 years and had frequently been at war with each other.3. Why does the author include the information that Mayan cities had “flourished for over 500 years and had frequently been at war with each other”?A. To identify a possible reason for the eventual collapse of Mayan societyB. To make the point that war and social unrest alone do not account for the Mayan collapseC. To explain why recent studies argue that human actions were responsible for the Mayan collapseD. To provide evidence that frequent wars weakened Mayan society only very gradually4. According to paragraph 3, recent studies claim which of the following about the Mayan collapse?A. It was caused primarily by frequent wars between rivalcity-states.B. It was caused by a single sudden event.C. It was preceded by social unrest in northern city-states.D. It began in southern city-states and spread to others.【Paragraph 4】But what about the possibility of food shortage? These could have come about through either natural or humanly induced changes in the environment. Increasingly fierce competition between Mayan cities led to an upsurge of monument construction during the eighth and ninth centuries A.D, which would have placed added strain on agricultural production and expansion. Interstate rivalry may hence have pushed the Maya toward overexploitation of their fragile ecosystem. Deforestation and soil erosion might ultimately have destroyed the capacity of the land to support the high population levels of the Mayan cities, leading to famine, social unrest, and the collapse of the major Mayan centers.5. All of the following are mentioned in paragraph 4 as possible direct or indirect causes of food shortages EXCEPTA. increased monument constructionB. rivalries between statesC. deforestation and stationD. introduction of new crops【Paragraph 5】Yet it may be incorrect to lay the blame entirely on human action. Several of the lowland cities, such as Tikal, appear to have depended heavily on the cultivation of raised fields set in the marshy depressions known as bajos, which today flood intermittently in the rainy season but may originally have been permanent lakes. The raise-field system of intensive cultivation (created by digging surrounding canals and using the soil removed to elevate the fields for planting) allows year-roundfood production through the constant supply of soil nutrients that erode into the drainage ditches dug around the raised fields, nutrients that are then collected and replaced. Stable water levels were essential to this subsistence system, but evidence from Lake Chichancanab in Yucatan shows that between A.D 800 and A.D 1000 this region suffered its driest period of climate in several thousand years. We may expect that as a result water level fell, and the raised fields in many areas became unusable. But the human response must be viewed through the lens of the social, political, and cultural circumstances. These exerted a powerful mediating effect on the way the Maya endeavored to cope with their difficulties. Had population levels been lower, the impact of the drought may not have been catastrophic, as it was, the Maya were already reaching the limits of the available subsistence capacity, and Mayan elites had espoused certain social and political agendas (including expensive warfare and competition with each other). It was against this specific background that a period of drought led quickly to crisis and collapse.6. The word “entirely” in the passage is closest in meaning toA. generallyB. clearlyC. completelyD. specifically7. According to paragraph 5, why did the raised fields in many areas become unusable?A. The marshy depressions around the fields flooded in the rainy seasonB. Intensive cultivation of the fields drained the soil of nutrients.C. The area where the fields were located experienced a drop in water levels.D. Unstable design caused the failure of the drainage ditches.8. According to paragraph 5, all of the following made it more difficult for the Maya to cope with effects of the drought EXCEPTA. failure to properly cultivate the fieldsB. high population levelsC. competition between Mayan groupsD. warfare【Paragraph 5】Yet it may be incorrect to lay the blame entirely on human action. ■Several of the lowland cities, such as Tikal, appear to have depended heavily on the cultivation of raised fields set in the marshy depressions known as bajos, which today flood intermittently in the rainy season but may originally have been permanent lakes. ■The raise-field system of intensive cultivation (created by digging surrounding canals and using the soil removed to elevate the fields for planting) allows year-round food production through the constant supply of soil nutrients that erode into the drainage ditches dug around the raised fields, nutrients that are then collected and replaced. ■Stable water levels were essential to this subsistence system, but evidence from Lake Chichancanab in Yucatan shows that between A.D 800 and A.D 1000 this region suffered its driest period of climate in several thousand years. ■We may expect that as a result water level fell, and the raised fields in many areas became unusable. But the human response must be viewed through the lens of the social, political, and cultural circumstances. These exerted a powerful mediating effect on the way the Maya endeavored to cope with their difficulties. Had population levels been lower, theimpact of the drought may not have been catastrophic, as it was, the Maya were already reaching the limits of the available subsistence capacity, and Mayan elites had espoused certain social and political agendas (including expensive warfare and competition with each other). It was against this specific background that a period of drought led quickly to crisis and collapse.9. Look at the four squares【■】that indicate where the following sentence could be added to the passage. Nature apparently also contributed to the food shortages.Where would the sentence best fit?10.【Directions】An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.Since the discovery of the Mayan ruins in the 1830s, researchers have tried to explain the collapse of Mayan civilization.●●●Answer choicesA. The Mayan attempt to develop intensive agricultural methods to support large populations in relatively small areas probably was unsuccessful and could have caused the Mayan collapse.B. The discovery of intact pyramids submerged in vegetationamong the Mayan ruins led researchers to believe that Mayan cities were simply overgrown rather than catastrophically destroyed.C. Warfare and rivalry between Mayan states may have caused food shortages that contributed to the eventual collapse of Mayan civilization.D. Early theories that the Mayan collapse was a sudden, catastrophic event were followed by views that treated the collapse as a gradual process.E. The continuing warfare and social unrest that started in the North and spread to the South provided researchers with evidence that the Mayan collapse took hundreds of years to occur.F. Drought between A. D. 800 and A.D. 1000 likely caused the Mayan system of intensive irrigated agriculture to fall, which could have brought about a rapid collapse of the Mayan states.。
GMAT考试阅读练习题目及解析
GMAT考试阅读练习题目及解析一、阅读理解练习题目题目1阅读以下段落，回答问题。
"The rise of the internet has transformed the way we gather information. With the click of a button, we have access to a vast amount of knowledge that was once difficult to obtain. However, this easy access to information also brings challenges, such as the overload of data and the difficulty in distinguishing between accurate and inaccurate information."1. What is the main idea of the passage?2. According to the passage, what are the benefits of the internet?3. What challenges does the easy access to information bring?题目2阅读以下段落，回答问题。
"Climate change is one of the most pressing global issues of our time. The Earth's climate is changing rapidly, and this is largely due to human activities, such as burning fossil fuels and deforestation. These activities release large amounts of greenhouse gases into the atmosphere, which trap heat and cause the Earth's temperature to rise. This phenomenon, known as global warming, has serious consequences for our planet, including rising sea levels, extreme weather events, and the loss of biodiversity."1. What is the main idea of the passage?2. According to the passage, what are the causes of climate change?3. What are the consequences of global warming?二、阅读理解练习题目解析解析11. main idea: The main idea of the passage is to discuss the impact of the internet on the way we gather information, highlighting both the benefits and the challenges it brings.2. benefits of the internet: The passage mentions that the easy access to information is one of the benefits of the internet.3. challenges of easy access to information: The passage states that the easy access to information brings challenges such as data overload and the difficulty in distinguishing between accurate and inaccurate information.解析21. main idea: The main idea of the passage is to discuss the issue of climate change and its consequences, emphasizing the role of human activities in causing global warming.2. causes of climate change: The passage mentions that burning fossil fuels and deforestation are two of the main causes of climate change.3. consequences of global warming: The passage lists several consequences of global warming, including rising sea levels, extreme weather events, and the loss of biodiversity.通过以上练习题目及解析，可以帮助考生提高GMAT考试的阅读理解能力。
TPO-14 Reading 2 阅读译文
Maya Water Problems玛雅的水源问题To understand the ancient Mayan people who lived in the area that is today southern Mexico and Central America and the ecological difficulties they faced, one must first consider their environment, which we think of as “jungle" or 'tropical rainforest." This view is inaccurate, and the reason proves to be important. Properly speaking, tropical rainforests grow in high-rainfall equatorial areas that remain wet or humid all year round. But the Maya homeland lies more than sixteen hundred kilometers from the equator, at latitudes 17 to 22 degrees north, in a habitat termed a “seasonal tropical forest." That is, while there does tend to be a rainy season from May to October, there is also a dry season from January through April. If one focuses on the wet months, one为了了解生活在今天南墨西哥和中美中地区的古玛雅人种以及他们所面对的生态困境，那么我们必须先研究他们的环境，也就是今天我们所谓的“丛林”或者“热带雨林”。
2022考研英语阅读喜马拉雅山受到污染
2022考研英语阅读喜马拉雅山受到污染Pollution in the Himalayas Time to call the sweep?喜马拉雅山受到了污染是时候呼吁清扫了吗?Soot gets everywhere. Even into the world s highest mountains处处都充满着烟灰，甚至扩散到了世界的最高山。
THE Himalayas and the adjacent Tibetan plateau are sometimes referred to as the Earth sthird pole, because of the amount of ice they host. They are also known as Asia s watertower. Their glaciers feed the continent s largest riversand those, in turn, sustain some 1.5billion people. Many studies suggest, though, that the Himalayan glaciers have been shrinkingover the past few decades. This has usually been attributed to rising air temperatures, butclimate researchers have now come to realise that tiny airborne particles of soot and dustare also to blame. Being dark, they absorb sunlight. And that warms their surroundings.喜马拉雅山及其邻近的青藏高原有时被称作是地球第三极，这是由于它们身上掩盖着大量的冰雪。
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the deep ocean,as its mixing time is close to the observed 800-year lag.Finally,the situation at Termination III dif-fers from the recent anthropogenic CO 2in-crease.As recently noted by Kump (38),we should distinguish between internal influences (such as the deglacial CO 2increase)and exter-nal influences (such as the anthropogenic CO 2increase)on the climate system.Although the recent CO 2increase has clearly been imposed first,as a result of anthropogenic activities,it naturally takes,at Termination III,some time for CO 2to outgas from the ocean once it starts to react to a climate change that is first felt in the atmosphere.The sequence of events during this Termination is fully consistent with CO 2partic-ipating in the latter ϳ4200years of the warm-ing.The radiative forcing due to CO 2may serve as an amplifier of initial orbital forcing,which is then further amplified by fast atmospheric feed-backs (39)that are also at work for the present-day and future climate.References and Notes1.J.R.Petit et al.,Nature 399,429(1999).2.A.Neftel,H.Oeschger,T.Staffelbach,B.Stauffer,Nature 331,609(1988).3.D.Raynaud et al.,Science 259,926(1993).4.J.M.Barnola,D.Raynaud,Y.S.Korotkevich,C.Lorius,Nature 329,408(1987).5.D.M.Sigman,E.A.Boyle,Nature 407,859(2000).6.In 1999,Fischer et al .(30)estimated that the increase of CO 2lagged Vostok temperature by 600Ϯ400years at the start of the last three Terminations,but the gas age–ice age difference at Vostok may be uncertain by 1000years (1)and thus obscures the phasing of gas variations with climate signals borne by the ice.7.The firn is the uppermost part of an ice sheet.It can be schematically divided into three zones with differ-ent properties concerning the movement of air:the convective zone in which the air is well mixed,the diffusive zone in which vertical transport is driven by molecular diffusion,and the nondiffusive zone in which air does not migrate vertically,and at the bottom of which the air is trapped (17).This en-trapped air is younger than the surrounding ice,which results in an age difference (⌬age)between the ice and the air bubbles that it contains.8.T.Blunier et al.,Geophys.Res.Lett.24,2683(1997).9.E.Monnin et al.,Science 291,112(2001).10.N.Caillon,J.Jouzel,J.Chappellaz,A.Grachev,unpub-lished data.ng,M.Leuenberger,J.Schwander,S.Johnsen,Science 286,934(1999).12.M.Leuenberger,ng,J.Schwander,J.Geophys.Res.104,22163(1999).13.J.P.Severinghaus,T.Sowers,E.Brook,R.Alley,M.Bender,Nature 391,141(1998).14.J.P.Severinghaus,J.Brook,Science 286,930(1999).15.N.Caillon et al.,J.Geophys.Res.106,31893(2001).16.The argon peak around 2760m has no counterpart inthe temperature record published in (1).In Fig.1B,we plotted the temperature profile that we deduced from the new deuterium measurements performed every 10cm (between 2700and 2800m).During the cooling phase of the interglacial,several abrupt tem-perature fluctuations occurred [especially around 235,000years (2740m)],which were not revealed by the temperature profile in (1).Those temperature variations could have affected the isotopic composi-tion of argon,making the argon peak at 2760m.However,the sampling frequency in this depth range (2775to 2750m)does not allow access to a ␦40Ar record as precise as that which we obtained during the Termination (i.e.,between 2830and 2775m)and does not allow a peak-to-peak correlation.17.T.A.Sowers,M.Bender,D.Raynaud,Y.S.Korotkev-ich,J.Geophys.Res.97,15683(1992).18.Dynamic densification firn models accounting for heattransfer are now under development.First results pre-dict that part of the measured argon signal should be a result of thermal diffusion (40,41).Those models sug-gest that despite the slow time scale of warming during the Termination,there is still a small residual temper-ature gradient left over after thousands of years,be-cause of the low thermal conductivity of the firn.The models generate a temperature gradient between sur-face and close-off region of about 3K,which leads to a thermal diffusion signal of about 0.11‰using mea-sured thermal diffusion coefficients (19,42).The use of a precise record of ␦15N,which is more sensitive to thermal diffusion than ␦40Ar/4,over the Termination should be useful to confirm the small thermal diffusion signal predicted by their models.Indeed,␦15N data should have a slightly larger value than ␦40Ar/4to be consistent with the presence of thermal diffusion signal (13).However,a precise record of ␦15N for Termination III is not available (fig.S1).19.J.P.Severinghaus,A.Grachev,B.Luz,N.Caillon,Geochim.Cosmochim.Acta 67,325(2003).20.L.Arnaud,J.-M.Barnola,P.Duval,in Physics of IceCore Records ,T.Hondoh,Ed.(Hokkaido Univ.Press,Sapporo,Japan,2000),pp.285–305.21.C.Lorius et al.,Nature 316,591(1985).22.The deuterium content of the snow in East Antarctica islinearly related to the surface temperature of the pre-cipitation site.Jouzel and colleagues (43)have reviewed all relevant information focusing on the East Antarctic Plateau where both model and empirical isotope-tem-perature estimates are bining arguments coming from the isotopic composition of the air bub-bles,from constraints with respect to ice core chronol-ogies,from atmospheric general circulation models,and from isotopic general circulation models (see references herein),the authors suggest that,unlike for Greenland,the present-day spatial isotope-temperature slope can be taken as a surrogate of the temporal slope to inter-pret glacial-interglacial isotopic changes at sites such as Vostok.23.O.Watanabe et al .,Nature ,in press.24.J.P.Severinghaus,A.Grachev,M.Battle,Geochem.Geo-phys.Geosyst.2,Paper no.2000GC000146(2001).25.N.Caillon,thesis,University of Paris 6,France (2001).26.M.Battle et al .,Nature 383,231(1996).27.The nondiffusive zone is at the bottom of the firn andthus warms several hundred years after the surface because of the slow diffusion of heat through the firn (4).Additionally,the low accumulation rates at Vostok make the downward transport of firn physical proper-ties rather slow (potentially spanning thousands ofyears).For example,if strong winds during the glacial periods created wind-packed layers that later impeded gas diffusion,thus creating a very thick nondiffusive zone,these layers would take several thousand years to be transported down to the nondiffusive zone.28.T.Sowers,M.Bender,D.Raynaud,Y.S.Korotkevich,J.Orchado,Paleoceanography 6,669(1991).29.J.Jouzel et al.,Quat.Sci.Rev.21,307(2002).30.H.Fischer,M.Wahlen,J.Smith,D.Mastroianni,B.Deck,Science 283,1712(1999).31.C.Genthon et al.,Nature 329,414(1987).32.N.J.Shackleton,Science 289,1897(2000).33.H.J.Smith,H.Fischer,M.Wahlen,D.Mastroianni,B.Deck,Nature 400,248(1999).34.J.R.Toggweiler,Paleoceanography 14,572(1999).35.B.Stephens,R.Keeling,Nature 404,171(2000).36.J.H.Martin,R.M.Gordon,S.E.Fitzwater,Nature 345,156(1990).37.W.S.Broecker,G.M.Henderson,Paleoceanography 13,352(1998).38.L.R.Kump,Nature 419,188(2002).39.C.Lorius,J.Jouzel,D.Raynaud,J.Hansen,H.Le Treut,Nature 347,139(1990).40.J.Schwander,personal communication.41.C.Goujon,personal communication.42.A.M.Grachev and J.P.Severinghaus,Geochim.Cos-mochim.Acta 67,345(2003).43.J.Jouzel et al .,J.Geophys.Res .,in press.44.L.Pe ´pin,D.Raynaud,J.-M.Barnola,M.F.Loutre,J.Geophys.Res.106,31885(2001).45.We acknowledge the effort of the Russian Antarctic expeditions (RAE),the division of Polar Programs (NSF),and the Institut Polaire Paul Emile Victor (IPEV )for their participation in the Vostok Project.We thank T.Sowers,M.Leuenberger,and J.Schwander for their pertinent and useful reviews;and J.Chappellaz,V.Masson-Del-motte,J.-R.Petit,F.Parrenin,H.Gildor,L.Pe ´pin,M.Bender,R.Keeling,ndais,V.Caillon,C.Gougon,and B.Bellier for help and for fruitful comments and discus-sions.This work was supported by the French Pro-gramme National d’E´tudes de la Dynamique du Climat (PNEDC),the CEA,the Balzam Foundation,the Europe-an program Pole-Ocean-Pole (POP EVK2-2000-00089),by NSF grants OPP 9725305and ATM 9905241(J.P.S.),and by recruitment funds from the Scripps Institution of Oceanography.Supporting Online Material/cgi/content/299/5613/1728/DC1Fig.S125September 2002;accepted 10February 2003Climate and the Collapse ofMaya CivilizationGerald H.Haug,1*†Detlef Gu ¨nther,2Larry C.Peterson,3Daniel M.Sigman,4Konrad A.Hughen,5Beat Aeschlimann 2In the anoxic Cariaco Basin of the southern Caribbean,the bulk titanium content of undisturbed sediment reflects variations in riverine input and the hydro-logical cycle over northern tropical South America.A seasonally resolved record of titanium shows that the collapse of Maya civilization in the Terminal Classic Period occurred during an extended regional dry period,punctuated by more intense multiyear droughts centered at approximately 810,860,and 910A.D.These newdata suggest that a century-scale decline in rainfall put a general strain on resources in the region,which was then exacerbated by abrupt drought events,contributing to the social stresses that led to the Maya demise.Paleoclimatologists have developed an increas-ingly precise record of climate change for the past few millennia,covering the same span of time over which literate human societies devel-oped.Until recently,archaeologists and histori-ans have lacked information about short-term climate change during the period of human societal evolution,being forced into the as-sumption that global climate has been nearly invariant for at least the past 6000years.How-ever,high-resolution paleoclimate records from ice cores,tree rings,and some deep-sea and lacustrine sediments now make it clear that climatic shifts did occur within the late Holo-cene and that these often coincided with twists and turns in human history(1).Unfortunately, the limitations of temporal resolution and chro-nology in paleoclimatic records still present a major obstacle to the development of a globally meaningful view of Holocene climatic changes and their role in social change.Here we report data from annually lami-nated sediments of the anoxic Cariaco Basin off northern Venezuela(Fig.1).Using mea-surements of bulk sediment chemistry,we developed a record of varying river-derived inputs having roughly bimonthly resolution for the period from700to950 A.D.,an interval known as the Terminal Classic Peri-od,during which Classic Maya civilization collapsed in the lowlands of the Yucatan Peninsula(Fig.1).Our data show a clear link between the chronology of regional drought and the demise of Classic Maya culture.This study focused on the Holocene sedi-ment sequence recovered in Ocean Drilling Program(ODP)holes1002C and1002D (10°42.73ЈN,65°10.18ЈW;water depth,893m) in the Cariaco Basin(2).These rapidly depos-ited(ϳ30cm per thousand years)organic-rich sediments are visibly laminated and devoid of preserved benthic faunas,indicating anoxic depositional conditions and no disturbance from burrowing.As an index for regional hy-drologic conditions,we used the bulk titanium (Ti)content as a recorder of terrigenous sedi-ment delivery to the Cariaco Basin from the surrounding watersheds(3,4).Previously re-ported Ti data(4)for the past2000years from hole1002C(Fig.2,bottom)were obtained at 2-mm measurement intervals(ϳ4to5years) (5).Details of the accelerator mass spectrome-try14C-based age model for these data and the conversion to calendar years can be found in (4).For this study,we subsequently analyzed a 30-cm slab sample from accompanying hole 1002D at ultrahigh resolution(50-m measure-ment spacing)(5).Offset scans along the face of the slab indicated that the hole1002D data were reproducible at the50-m level,which is consistent with observations that the laminae are undisturbed.In the interval of hole1002D from which the30-cm slab sample was taken,the typical varve(that is,one light-dark laminaepair)isϳ0.4to0.5mm thick.Given the50-mmeasurement spacing,each varve is split byabout eight analyses,yielding roughly bi-monthly resolution and clear resolution of theannual signal.Ti data from this slab samplewere readily correlated to the existing Ti datafrom hole1002C(Fig.2).The connection between rainfall and riv-erine detrital input is recorded in the laminat-ed nature of Cariaco Basin sediments.Pairedannual laminations in the sediments are theresult of large changes in rainfall and windthat occur in this region in response to sea-sonal shifts in the position of the IntertropicalConvergence Zone(ITCZ)(Fig.1)and itsassociated belt of convective activity(6,7).Light-colored laminae consist mostly of bio-genic components deposited during the drywinter-spring upwelling season,when theITCZ is located at its southernmost positionand trade winds along the Venezuelan coastare strong.In contrast,dark laminae are de-posited during the regional rainy season(summer-fall),when the ITCZ migrates to itsmost northerly position,almost directly overthe Cariaco Basin.Dark-colored laminae arerich in terrigenous grains and record higherinputs of Ti and other lithophilic elements.Our interpretation of bulk Ti content as anindex of regional hydrologic change,reflect-ing variations of the mean ITCZ position withtime,is supported by comparison of the Ho-locene Cariaco record(4)with independentpaleoclimatic data from nearby Lake Valen-cia(8),Haiti(9),the Yucatan(10),and LakeTiticaca in Peru(11).Ti concentrations in sediments(ODP hole1002C)deposited over the past2000years(Fig.2,bottom)were lowest betweenϳ500and200years before the present(yr B.P.),indicating dry conditions during the“LittleIce Age”(4).Higher Ti concentrations andwet conditions characterized the time intervalfrom1070to850yr B.P.,a portion of thetime span often termed the Medieval WarmPeriod.Before the sharp Ti rise atϳ1070yrB.P.(930A.D.),sediment Ti concentrationswere of intermediate value,with the excep-tion of pronounced minima centered in our1Department of Earth Sciences,2Department of Chemistry,ETH,CH-8092Zu¨rich,Switzerland. 3Rosenstiel School of Marine and Atmospheric Sci-ence,University of Miami,Miami,FL33149,USA. 4Department of Geosciences,Princeton University, Princeton,NJ08544,USA.5Department of Marine Chemistry and Geochemistry,Woods Hole Oceano-graphic Institution,Woods Hole,MA02543,USA. *To whom correspondence should be addressed.E-mail:haug@gfz-potsdam.de.†Present address:Geoforschungszentrum Potsdam, D-14473Potsdam,Germany.Fig.1.Seasonal variations in the mean position of the ITCZ over Mesoamerica and northern South America,illustrated for typical summer(September)(top)and winter(March)(bottom)conditions. These variations control the pattern and timing of regional rainfall.Numbers and colors reflect sea surface temperatures in degrees Celsius.Locations of the Cariaco Basin study area and the Maya lowlands are indicated.Both regions are similarly affected by seasonal and longer term changes in the position of the ITCZ.chronology at about 1750and 1650yr B.P.and later at 1200yr B.P.Details of this interval are more clearly visible in our new record from the 30-cm slab sample from ODP hole 1002D (Fig.2,top).Though highly smoothed (with a 30-point running mean),the ultrahigh-resolution 50-m measure-ments from the slab sample faithfully repro-duce trends visible in the 2-mm analyses of parallel hole 1002C.Expansion of the upper 9cm of the 50-m slab sample data (Fig.3;three-point running mean)shows a series of four distinct Ti minima at slab depths of ϳ12,38,58,and 78mm.These are interpreted as evidence for separate multiyear drought events in the region.It has been suggested that recurrent pat-terns of drought played an important role in the complex history of the Maya (10,12,13).The Maya civilization developed in a season-al desert and depended on a consistent rain-fall cycle to support agricultural production.Most of the rain falls during the summer,when the ITCZ sits at its northernmost posi-tion over the Yucatan (Fig.1).During the winter,the ITCZ is located south of the low-lands and the climate is dry.Hence,the centerof Maya civilization was located in the same climatic regime as the Cariaco Basin,with both areas near the northern limit of seasonal ITCZ motion.An extended southward dis-placement of the ITCZ,as indicated by low Ti in Cariaco sediments,should lead to sim-ilar rainfall reduction in the Maya lowlands.In order to inhabit the Yucatan lowlands and to deal with normal seasonal variations in rainfall,the Maya developed various strate-gies to accumulate and store water.Cities were designed to catch the water from rain-fall,and quarries and excavations were con-verted into water reservoirs.The Maya also built on topographic highs to use the hydrau-lic gradient to distribute the water from ca-nals into complex irrigation systems (14,15).However,the human-engineered system ulti-mately depended on seasonal rainfall,be-cause much of the lowlands has only restrict-ed natural groundwater resources.During the Pre-Classic period before about 150A.D.,Maya culture flourished and the first major cities were built.Between ϳ150and 250A.D.,the first documented historical crisis hit the lowlands,which led to the “Pre-Classic abandonment ”(16)of major cities (Fig.2).However,populations recovered,cities were reoccupied,and Maya culture blossomed in the following centuries during the so-called Classic period.At the peak of the Classic,around 750A.D.,population estimates for the Maya lowlands range from 3million to 13million inhabitants (17,18).Between about 750and 950 A.D.,the Maya experienced a demographic disaster as profound as any other in human history.Dur-ing the Terminal Classic Collapse,many of the densely populated urban centers were abandoned permanently,and Classic Maya civilization came to an end.What happened?Although the Cariaco record cannot provide a complete explanation,it supports the view that changes in rainfall played a critical role.We suggest that the rapid expansion of Maya civilization from 550to 750 A.D.during climatically favorable (relatively wet)times resulted in a population operating at the limits of the environment ’s carrying capacity,leav-ing Maya society especially vulnerable to multiyear droughts.Earlier paleoclimate records from nearby lakes have provided compelling evidence that climate change and aridity played a key role in the collapseofFig.2.(Bottom )Bulk Ti content [three-point running mean of 2-mm resolution measurements (4)]at ODP hole 1002C in the Cariaco Basin dur-ing the past 2000years.The timing of well-known climate events (such as the Little Ice Age)and major events in the history of Maya civili-zation are shown.The Pre-Classic abandon-ment and the Termi-nal Classic Collapse of Maya culture coincid-ed with phases of low riverine-derived Ti in-put to the Cariaco Ba-sin and with inferred dry conditions in the region.(Top )The bulk Ti content (30-point running mean of 50-m resolution ana-lyses)of a 30-cm-long slab sample from companion ODP hole 1002D in the time in-terval from about 1.8to 1.0thousand years ago confirms these trends and shows in-creased detail.Periods of drought,marked by low Ti values in the sediments,are likelythe result of climatic conditions that prevented the ITCZ and its associated rainfall from penetrating as far north as normal.Maya culture (10,13).However,the time resolution of these records has to date been insufficient to provide a precise test of the chronological relationships between climate and cultural changes,despite clear evidence that both occurred.The Cariaco record pro-vides a starting point for integrating these changes into a common history.Archaeological studies of Maya sites have led to substantial debate over the timing and regional patterning of the Terminal Classic col-lapse (16).Indeed,regional diversity in the tim-ing of cultural transformations during the Ter-minal Classic period has been used as one ar-gument against drought as a causal factor.The evidence from the Cariaco Basin for a number of distinct multiyear droughts,superimposed on an already generally dry period,may help ex-plain why the so-called collapse was drawn out in time and was regionally variable.The radiocarbon age control for hole 1002C (4)is sufficient to constrain the broad low Ti interval highlighted in Fig.2as cen-tered in the 9th century A.D.A tight match with the independently dated megadrought event in the Lake Chichancanab sediment record (10,13)gives confidence in this ab-solute age assignment.Taking a date of 930A.D.for the sharp Ti rise that marks the start of Medieval Warm conditions,the counting of seasonal Ti minima can be used to assign ages to the events below.By this scheme,the distinct Ti minima at depths of ϳ12,38,58,and 78mm in the hole 1002D slab sample (Fig.3)mark multiyear drought events that began at about 910,860,810,and 760A.D.,respectively.Not counting the duration of the droughts,the number of varves between drought events indicates a spacing of approx-imately 40to 47years (Ϯ5),a number that agrees well with observations of sub-peaks in the Lake Chichancanab sedimentdensity record at about 50-year intervals (13).Dry conditions beginning about 760A.D.are clearly marked in the Cariaco Ti record by two large inferred rainfall minima (Fig.3).Over the subsequent ϳ40years,there ap-pears to have been a slight long-term drying trend.This culminated in roughly a decade of more intense aridity that,within the limits of the present chronology,began at about 810A.D.Drought at about 860A.D.is recorded by a distinct interval of minimum Ti concen-trations,indicating a short (ϳ3years)but apparently severe event at that time.Finally,low Ti contents in the Cariaco Basin se-quence indicate the onset of yet another drought at about 910A.D.,this one estimated to have lasted for ϳ6years.Mayanists generally agree that there is strong evidence for regional variability in the Terminal Classic collapse in the archaeological record (16).Most would also concur that the collapse occurred first in the southern and cen-tral Yucatan lowlands,and that many areas of the northern lowlands underwent a similar de-cline a century or so later.A more controversial tripartite pattern of city abandonment (12),based on analysis of the last dates carved into local monuments (stelae),has been proposed,which calls for separate phases of collapse that terminated respectively at about 810,860,and 910A.D.Noting a similarity between these end dates and the timing of especially severe cold spells indicated in Swedish tree ring records (19),Gill (12)speculated that periods of coin-cident drought in Mesoamerica led to the Maya demise.There is considerable debate about us-ing the last entries on stone monuments as an accurate record of city abandonment,and only larger (rank order 10or greater)Maya sites were considered in the analysis of (12).Nev-ertheless,within the uncertainty of our age model,the proposed end dates match the threemost severe drought events inferred from the Cariaco Basin record.Considerable variability exists in the dis-tribution and quality of natural water sources in the Yucatan lowlands (12),a factor that would surely come into play during periods of drought.Although the northern lowlands are characterized by the lowest amounts of annual average rainfall,collapsed cenotes in this region provide direct access to the rela-tively shallow groundwater table.In the cen-tral lowlands,some fresh water is available in and around the Pete ´n Lake district.Towards the west and south,however,access to groundwater is scarce,and rainfall was the primary source of water for Maya cities.Dur-ing sustained drought,access to groundwater was likely an important factor in determining which large population centers could survive.The control of artificial water reservoirs by Maya rulers may also have played a role in both the florescence and the collapse of Maya civi-lization.Noting that the scale of artificial water control seems to correlate with the degree of political power of Maya cities,it has been sug-gested (20)that drought may have undermined the institution of Maya rulership when existing ceremonies and technologies failed to provide sufficient water.In this view,the larger regional centers suffered most,whereas secondary and minor Maya population centers that were less dependent on artificial reservoirs and water control were less affected.No one archaeological model is likely to capture completely a phenomenon as complex as the Maya decline.Nevertheless,the Cariaco Basin sediment record provides support for the hypothesis that regional drought played an im-portant role in the collapse of Classic Maya civilization,and it provides a temporal template against which archaeological data can be com-pared.Drought conditions may also havebeenFig.3.Bulk Ti content (three-point running mean of 50-m reso-lution analyses)cen-tered on the time in-terval of the collapse of Maya civilization in the Terminal Classic Period.This figure represents an ex-panded view of the 90-mm slab sample section highlighted in Fig.2,top.The as-signment of ages for prominent drought events (Ti minima)is based on a date of 930A.D.for the sharp rise in Ti (Fig.2)thatmarks the local onset of Medieval Warm conditions,and on varve counting below and throughout this interval.The ability to resolve individual years based on seasonal Ti variations allows for precise esti-mation of the duration of drought events and of the time between them,although the absolute age of the floating time window is less certainbecause of the dependence on radiocarbon control with larger errors (Ϯ30years).Evidence presented here for separate and more severe multiyear drought events superimposed on an extended period of overall reduced precipitation may help to explain the multiple stages and regional variability of the Maya collapse.responsible for the earlier Pre-Classic abandon-ment of cities that occurred between about150 and250A.D.These periods of drought are probably the result of climatic conditions that prevented the ITCZ and its associated rainfall from penetrating as far north as normal.Given the perspective of our long time series,it would appear that the droughts we have highlighted were the most severe to affect this region in the first millennium A.D.The intervals of peak drought were brief,each lasting betweenϳ3 and9years,but they occurred during an extend-ed period of reduced overall precipitation that may have already pushed the Maya system to the verge of collapse.References and Notes1.P.B.deMenocal,Science292,667(2001).2.H.Sigurdsson et al.,Proc.ODP Init.Rep.165,359(1997).3.L.C.Peterson,G.H.Haug,K.A.Hughen,U.Ro¨hl,Science290,1947(2000).4.G.H.Haug,K.A.Hughen,D.M.Sigman,L.C.Peter-son,U.Ro¨hl,Science293,1304(2001).5.Analyses for the Holocene section at2mm reso-lution were obtained with a profiling x-rayfluores-cence scanner at the University of Bremen(4).TheTi element mapping at50m resolution was car-ried out with a Ro¨ntgenanalytik Eagle II MicroX-Ray Fluorescence system at ETH Zu¨rich(with theuse of an Rh tube at40kV and800mA).Thesediment slab samples from hole1002D were mea-sured in two parallel and overlapping line scans(sample length,15cm).For optimum counting,ameasurement time of24hours for each sampleslab was applied.6.L.C.Peterson,J.T.Overpeck,N.G.Kipp,J.Imbrie,Paleoceanography6,99(1991).7.K.A.Hughen,J.T.Overpeck,L.C.Peterson,R.F.Anderson,Geol.Soc.Spec.Pub.116,171(1996).8.J.P.Bradbury et al.,Science214,1299(1981).9.D.A.Hodell et al.,Nature352,790(1991).10.D.A.Hodell,J.H.Curtis,M.Brenner,Nature375,391(1995).11.P.A.Baker et al.,Science291,640(2001).12.R.B.Gill,The Great Maya Droughts:Water,Life and Death(Univ.of New Mexico Press,Albuquerque,NM,2000).13.D.A.Hodell,M.Brenner,J.H.Curtis,T.Guilderson,Science292,1367(2001).14.R.E.W.Adams,Science251,632(1991).15.V.L.Scarborough,Natl.Geogr.Res.Explor.10,184(1994).16.D.Webster,The Fall of the Ancient Maya(Thamesand Hudson,London,2002).17.T.P.Culbert,D.S.Rice,Precolumbian PopulationHistory in the Maya Lowland s(Univ.of New MexicoPress,Albuquerque,NM,1990).18.R.Sharer,The Ancient Maya(Stanford Univ.Press,Stanford,CA,1994).19.W.Karle´n,Climatic Changes on a Yearly to MillenniaBasis:Geological,Historical and Instrumental Records(Reidel,Dordrecht,Netherlands,1984).20.L.J.Lucero,Am.Anthropol.104,814(2002).21.We thank D.Hodell,J.Bollmann,B.Fagan,C.Rooth,K.Broad,H.Thierstein,and an anonymous referee forhelpful discussions and critical comments.This re-search used samples provided by the Ocean DrillingProgram(ODP).The ODP is sponsored by NSF andparticipating countries under the management ofJoint Oceanographic Institutions(JOI).Supported bythe Schweizer Nationalfonds and NSF,and by BritishPetroleum and the Ford Motor Company to D.M.S.through the Princeton Carbon Mitigation Initiative.13November2002;accepted28January2003Evolution of Virulence in a Plant Host-Pathogen Metapopulation Peter H.Thrall*and Jeremy J.BurdonIn a wild plant–pathogen system,host resistance and pathogen virulence varied markedly among local populations.Broadly virulent pathogens occurred more frequently in highly resistant host populations,whereas avirulent pathogens dominated susceptible populations.Experimental inoculations indicated a neg-ative trade-off between spore production and virulence.The nonrandom spatial distribution of pathogens,maintained through time despite high pathogen mobility,implies that selection favors virulent strains of Melampsora lini in resistant Linum marginale populations and avirulent strains in susceptible pop-ulations.These results are consistent with gene-for-gene models of host-pathogen coevolution that require trade-offs to prevent pathogen virulence increasing until host resistance becomes selectively neutral.Infectious disease has a major influence on the demography of human,plant,and animal populations.It is generally accepted that vari-ation in host resistance is of central impor-tance to patterns of disease incidence and prevalence(1).High variability has been reported for several host loci(e.g.,major histocompatibility complex and/or human leukocyte antigens)linked to disease(1,2), consistent with the selective forces imposed by pathogens(3).At the population level, there are indications that pathogen diversity can determine the dynamics of epidemics (e.g.,the slow spread of HIV in some regions may be linked to low genetic variation in particular viral groups)(4).Some work has revealed negative relationships between gen-eral measures of host diversity and diseaseincidence(5–7).More specifically,work onthe genetically well-studied Linum-Melamp-sora plant-pathogen system has shown nega-tive correlations between population resis-tance diversity and disease prevalence(8).However,with a few notable exceptions(9,10),remarkably little effort has been directedat investigating causal links between hostpopulation genetic structure and disease dy-namics.This is particularly surprising,giventhe potential for such variation to affectpathogen evolution and the emergence ofnew diseases(11,12).Most mathematical models of the dynam-ics of host-pathogen coevolution,and indeedmuch of our current thinking about geneticinteractions between hosts and parasites,have been shaped by the gene-for-gene par-adigm.Essentially,this hypothesis states thatfor each host resistance gene,there is a cor-responding avirulence gene in the pathogenwith which it interacts.For a resistant reac-tion to occur(i.e.,infection does not takeplace,as the host recognizes the presence ofthe pathogen),both the specific resistancegene in the host and the avirulence gene inthe pathogen must be present.In this context,virulence is defined as the ability of a patho-gen to overcome a given host resistance gene.At the population level,virulence can bethought of as the average ability of a patho-gen population to overcome the diversity ofresistance genes present in the correspondinghost population.The gene-for-gene conceptis derived from work on cultivated flax andan associated rust pathogen(13)but has sincebeen shown to occur in many other systemsinvolving interactions of plants with fungi,viruses,and some insects(14).One such wild gene-for-gene interaction oc-curs between L.marginale,an herbaceous pe-rennial endemic to southern Australia,and itshost-specific rust pathogen,M.lini.To date,17separate alleles conferring resistance to a widerange of pathogen isolates have been detectedin this interaction(15).During the growingseason,generations of the pathogen followone another in quick succession,leading tolocal epidemics.On the Kiandra Plain,thephenology of the host results in distinctcrashes in pathogen numbers as plants dieback to underground rootstocks at the end ofthe summer.M.lini is an aerially dispersed rust pathogenthat produces large numbers of urediosporesthat,like most other rust pathogens,may bedispersed large distances.For example,the ap-pearance of a novel pathotype(distinguished bypathogenic and molecular markers)in the Ki-andra area is believed to have resulted from amigration event ofϾ100km(16).In fieldexperiments assessing pathogen extinctionand recolonization in small populations of L.Commonwealth Scientific and Industrial Research Or-ganization(CSIRO)—Plant Industry,Centre for Plant Biodiversity Research,General Post Office Box1600, Canberra,ACT2601,Australia.*To whom correspondence should be addressed.E-mail:Peter.Thrall@csiro.au。