1、高考资源网（） 您身边的高考专家课时作业(十八)Unit 6Section Using language & Developing ideas.阅读理解ACalifornia has lost half its big trees since the 1930s, according to a study to be published Tuesday and climate change seems to be a major factor (因素)The number of trees larger than two feet across has declined by 50 perce
2、nt on more than 46 000 square miles of California forests, the new study finds. No area was spared or unaffected, from the foggy northern coast to the Sierra Nevada Mountains to the San Gabriels above Los Angeles. In the Sierra high country, the number of big trees has fallen by more than 55 percent
3、; in parts of southern California the decline was nearly 75 percent.Many factors contributed to the decline, said Patrick McIntyre, an ecologist who was the lead author of the study. Woodcutters targeted big trees. Housing development pushed into the woods. Aggressive wildfire control has left Calif
4、ornia forests crowded with small trees that compete with big trees for resources (资源)But in comparing a study of California forests done in the 1920s and 1930s with another one between 2001 and 2010, McIntyre and his colleagues documented a widespread death of big trees that was evident even in wild
5、lands protected from woodcutting or development.The loss of big trees was greatest in areas where trees had suffered the greatest water shortage. The researchers figured out water stress with a computer model that calculated how much water trees were getting in comparison with how much they needed,
6、taking into account such things as rainfall, air temperature, dampness of soil, and the timing of snowmelt (融雪)Since the 1930s, McIntyre said, the biggest factors driving up water stress in the state have been rising temperatures, which cause trees to lose more water to the air, and earlier snowmelt
7、, which reduces the water supply available to trees during the dry season.1What is the second paragraph mainly about?AThe seriousness of bigtree loss in CaliforniaBThe increasing variety of California big trees.CThe distribution of big trees in California forests.DThe influence of farming on big tre
8、es in California.2Which of the following is wellintentioned but may be bad for big trees?AEcological studies of forests.BBanning woodcutting.CLimiting housing development.DFire control measures.3What is a major cause of the water shortage according to McIntyre?AInadequate snowmelt. BA longer dry sea
9、son.CA warmer climate. DDampness of the air.4What can be a suitable title for the text?ACalifornias Forests: Where Have All the Big Trees Gone?BCutting of Big Trees to Be Prohibited in California SoonCWhy Are the Big Trees Important to California Forests?DPatrick McIntyre: Grow More Big Trees in Cal
10、iforniaBHow does an ecosystem (生态系统) work? What makes the populations of different species the way they are? Why are there so many flies and so few wolves? To find an answer, scientists have built mathematical models of food webs, noting who eats whom and how much each one eats.With such models, sci
11、entists have found out some key principles operating in food webs. Most food webs, for instance, consist of many weak links rather than a few strong ones. When a predator (掠食动物) always eats huge numbers of a single prey (猎物), the two species are strongly linked; when a predator lives on various spec
12、ies, they are weakly linked. Food webs may be dominated by many weak links because that arrangement is more stable over the long term. If a predator can eat several species, it can survive the extinction (灭绝) of one of them. And if a predator can move on to another species that is easier to find whe
13、n a prey species becomes rare, the switch allows the original prey to recover. The weak links may thus keep species from driving one another to extinction.Mathematical models have also revealed that food webs may be unstable, where small changes of top predators can lead to big effects throughout en
14、tire ecosystems. In the 1960s, scientists proposed that predators at the top of a food web had a surprising amount of control over the size of populations of other speciesincluding species they did not directly attack.And unplanned human activities have proved the idea of topdown control by top pred
15、ators to be true. In the ocean, we fished for top predators such as cod on an industrial scale, while on land, we killed off large predators such as wolves. These actions have greatly affected the ecological balance.Scientists have built an earlywarning system based on mathematical models. Ideally,
16、the system would tell us when to adapt human activities that are pushing an ecosystem toward a breakdown or would even allow us to pull an ecosystem back from the borderline. Prevention is key, scientists say, because once ecosystems pass their tipping point (临界点), it is remarkably difficult for the
17、m to return.5What have scientists discovered with the help of mathematical models of food webs?AThe living habits of species in food webs.BThe rules governing food webs of the ecosystems.CThe approaches to studying the species in the ecosystems.DThe differences between weak and strong links in food
18、webs.6A strong link is found between two species when a predator _.Ahas a wide food choiceBcan easily find new preyCsticks to one prey speciesDcan quickly move to another place7What will happen if the populations of top predators in a food web greatly decline?AThe prey species they directly attack w
19、ill die out.BThe species they indirectly attack will turn into top predators.CThe living environment of other species will remain unchanged.DThe populations of other species will experience unexpected changes.8What conclusion can be drawn from the examples in Paragraph 4?AUncontrolled human activiti
20、es greatly upset ecosystems.BRapid economic development threatens animal habitats.CSpecies of commercial value dominate other species.DIndustrial activities help keep food webs stable.CWho cares if people think wrongly that the internet has had more important influences than the washing machine? Why
21、 does it matter that people are more impressed by the most recent changes?It would not matter if these misjudgments were just a matter of peoples opinions. However, they have real impacts, as they result in misguided use of scarce resources.The fascination with the ICT (Information and Communication
22、 Technology) revolution, represented by the internet, has made some rich countries wrongly conclude that making things is so “yesterday” that they should try to live on ideas. This belief in “postindustrial society” has led those countries to neglect their manufacturing sector (制造业), with negative c
23、onsequences for their economies.Even more worryingly, the fascination with the internet by people in rich countries has moved the international community to worry about the “digital divide” between the rich countries and the poor countries. This has led companies and individuals to donate money to d
24、eveloping countries to buy computer equipment and internet facilities. The question, however, is whether this is what the developing countries need the most. Perhaps giving money for those less fashionable things such as digging wells, extending electricity networks and making more affordable washin
25、g machines would have improved peoples lives more than giving every child a laptop computer or setting up internet centres in rural villages. I am not saying that those things are necessarily more important, but many donators have rushed into fancy programmes without carefully assessing the relative
26、 longterm costs and benefits of alternative uses of their money.In yet another example, a fascination with the new has led people to believe that the recent changes in the technologies of communications and transportation are so revolutionary that now we live in a “borderless world”. As a result, in
27、 the last twenty years or so, many people have come to believe that whatever change is happening today is the result of great technological progress, going against which will be like trying to turn the clock back. Believing in such a world, many governments have put an end to some of the very necess
28、ary regulations on crossborder flows of capital, labour and goods, with poor results.Understanding technological trends is very important for correctly designing economic policies, both at the national and the international levels, and for making the right career choices at the individual level. How
29、ever, our fascination with the latest, and our undervaluation of what has already become common, can, and has, led us in all sorts of wrong directions.9Misjudgments on the influences of new technology can lead to _.Aa lack of confidence in technologyBa slow progress in technologyCa conflict of publi
30、c opinionsDa waste of limited resources10The example in Paragraph 4 suggests that donators should _.Atake peoples essential needs into accountBmake their programmes attractive to peopleCensure that each child gets financial supportDprovide more affordable internet facilities11What has led many gover
31、nments to remove necessary regulations?ANeglecting the impacts of technological advances.BBelieving that the world has become borderless.CIgnoring the power of economic development.DOveremphasizing the role of international communication.12What can we learn from the passage?APeople should be encoura
32、ged to make more donations.BTraditional technology still has a place nowadays.CMaking right career choices is crucial to personal success.DEconomic policies should follow technological trends.课时作业(十八).阅读理解A【语篇解读】本文是一篇说明文。文章介绍了加利福尼亚州的大树的数量急剧下降这一现象，并分析了其背后的原因。1答案与解析：A段落大意题。该题问的是第二段的主要内容。根据第二段内容尤其是本段中列
33、举的几个数据“50 percent.46 000 square miles.more than 55 percent.nearly 75 percent”可知，第二段主要介绍了加利福尼亚州的大树损失的严重性。故选A。2答案与解析：D推理判断题。根据第三段最后一句可知，防火措施的意图是好的，但是对大树不利。故选D。3答案与解析：C细节理解题。根据最后一段可知，温暖的气候是缺水的主要原因。故选C。4答案与解析：A标题概括题。根据全文及第二段第一句可知，文章介绍了加利福尼亚州的大树的数量急剧下降的现象，并分析了其背后的原因。A项“加利福尼亚的森林：所有的大树都去哪了？”概括了文章的主旨，适合作本文的
34、标题。故选A。B【语篇解读】本文是一篇说明文。最近科学家们建立了一些关于食物网的数学模型以帮助人们更好地了解生态系统的运作以及如何维持生态系统的平衡。5答案与解析：B细节理解题。根据第二段第一句可知，科学家利用食物网的数学模型发现了管理生态系统中食物网的一些重要原则。故选B。6答案与解析：C细节理解题。根据第二段第三句中的“When a predator (掠食动物) always eats huge numbers of a single prey (猎物), the two species are, strongly linked”可知，当一种掠食动物总是捕食某一种猎物时，说明这两类动物之
35、间的联系是很紧密的。故选C。7答案与解析：D推理判断题。该题问的是如果食物网顶端的掠食动物的数量急剧下降会发生什么。根据第三段中的“.small changes of top predators can lead to big effects throughout entire ecosystem.predators at the top of a food web had a surprising amount of control over the size of the populations of other speciesincluding species they did not
36、directly attack”可推知，食物网顶端的掠食动物的数量即使有一些小的变化也会对整个生态系统造成很大的影响，其他种类的动植物的数量会发生很大的变化。由此可推知，如果食物网顶端的掠食动物的数量急剧下降，其他种类的动植物的数量也会发生意想不到的变化。故选D。8答案与解析：A推理判断题。根据第四段最后一句，可知，那些例子表明，毫无控制的人类活动会严重影响生态平衡。故选A。C【语篇解读】本文是一篇议论文。文章阐述了盲目追赶和推崇新科技可能会带来的严重结果。9答案与解析：D细节理解题。该题问的是对新科技的误判会导致什么结果。根据第二段第二句可知，对科技的误判会导致稀有资源的误用，即资源的浪费。故选D。10答案与解析：A推理判断题。该题问的是第四段中的事例暗示捐助者们应该做什么。根据第四段内容，尤其是第四、五句可知，捐助者在捐助时应该考虑到人们的基本需求。故选A。11答案与解析：B推理判断题。该题问的是什么导致政府终止了必要的监管。根据第五段内容，尤其是第一、三句可推知，很多政府相信世界变成了无边界的世界交流而终止必要的监管。故选B。12答案与解析：B推理判断题。该题问的是我们能从文章中了解到什么。根据最后一句可推知，传统技术在当今社会仍然很重要。故选B。- 7 - 版权所有高考资源网