1、课时跟踪练30 Unit 5 The power of nature.阅读理解AIf humans pump enough carbon dioxide(CO2)into the atmosphere，stratocumulus clouds(层积云)could disappear，and the Earths temperature could climb sharply to heights not predicted in current climate models.It would burn the planet.Thats the conclusion of a paper pub
2、lished in the journal Nature Geoscience and described in detail by Natalie Wolchover for Quanta Magazine.As Wolchover explained，clouds have long been one of the great uncertainties of climate models.Computer models that easily capture the complexity and detail of most climate systems just arent powe
3、rful enough to predict worldwide changes in the behaviour of clouds.But clouds are important.They reflect sunlight away from the Earths surface.And stratocumulus clouds are those white blankets you might have seen as you look out the window of the airplane，rolling out below you and hiding the ground
4、.Researchers suspect that certain sudden jumps in temperature may have been caused by changes to clouds like these.For the new research，scientists modeled just a small patch of sky using a supercomputer.They found that if carbon dioxide levels reach about 1，200 parts per million(ppm)in the atmospher
5、e，stratocumulus clouds will break up.Thats a very high carbon dioxide concentration.Right now，levels have climbed past 410 ppma dangerous change from 280 ppm before the Industrial Revolution.But humans put more and more CO2 into the atmosphere every year.If current trends continue，the Earth could re
6、ach 1，200 ppm within 100 to 150 years.This could happen if our society doesnt follow through on any of its commitments to reduce emissions(排放物)，Wolchover reported.And even if it does，the result would be another 8 degrees Celsius of heat added to the global an average，on top of the dangerous changes
7、already underway due to greenhouse gases.Thats an enormous change，and it goes beyond predictions of worldwide ice melt and catastrophic sea level rise.And，once stratocumulus clouds are gone，Wolchover reported，they likely wouldnt reappear until atmospheric carbon dioxide levels dropped below where th
8、ey are currently.Theres still some uncertainty in the data.The 1，200 ppm figure could change as scientists look into the issue further.1What can we learn from Paragraph 2?AMost climate systems are not complex.BThe behaviour of clouds is uncertain and hard to predict.CTemperature changes affect strat
9、ocumulus clouds.DThe stratocumulus clouds protect planes from sunlight.2What does “it”refer to in Paragraph 4?AThe atmosphere.BThe earth.COur society. DThe result.3Which of the following statements would Wolchover most probably agree with ?AThe effects of CO2 emissions have been fully assessed.BStra
10、tocumulus clouds wont return if they are gone.CThe breakup of stratocumulus clouds could result in catastrophes.DOnce CO2 level reaches 1，200 ppm，stratocumulus clouds will go extinct.【语篇解读】本文主要介绍了人类如果继续向大气中排放二氧化碳可能造成的后果及原因。1解析：细节理解题。根据第二段中的“.clouds have long been one of the great uncertainties of cl
11、imate models.Computer models that easily capture the complexity and detail of most climate systems just arent powerful enough to predict worldwide changes in the behaviour of clouds.”可知，长期以来，云层一直是气候模式中很不确定的因素之一。轻易捕捉到大多数气候系统的复杂性和细节的计算机模型不够强大，无法预测世界范围内云雾状态的变化。由此可知，云雾状态是不确定的，很难预测。故选B项。答案：B2解析：词义猜测题。根据画
12、线词前一句中的“This could happen if our society doesnt follow through on any of its commitments to reduce emissions”可知，如果我们的社会不遵守减少排放物的承诺，在100到150年内地球二氧化碳的含量可能达到百万分之一千二。even if it does是对our society doesnt follow through.的一种让步情况，由此推知，it在此处指代our society，此处表示即使我们的社会遵守减少排放物的承诺，结果将是全球平均气温也会再增加8摄氏度。故选C项。答案：C3解析：
13、推理判断题。根据第三段中的“They found that if carbon dioxide levels reach about 1，200 parts per million(ppm)in the atmosphere，stratocumulus clouds will break up.”和第四段中的“If current trends continue，the Earth could reach 1，200 ppm within 100 to 150 years.on top of the dangerous changes already underway due to green
14、house gases.”以及第五段中的“Thats an enormous change，and it goes beyond predictions of worldwide ice melt and catastrophic sea level rise.”可知，当大气中的二氧化碳含量达到百万分之一千二百的时候，层积云就会散开，它所导致的变化是巨大的，其灾难性远大于全球冰层融化和海平面上升，即它所带来的灾难比全球冰层融化和海平面上升严重得多。综上可知，层积云散开会造成巨大灾难。故选C项。答案：CBMost dog owners are convinced that their fourl
15、egged friends know exactly what they mean when they use certain words like sit，stay or treat.However，researchers have always wondered whether dogs really understand human speech or if they rely on other information to get the meaning.For example，does the word “fetch”form a picture of a stick or ball
16、 in the dogs mind，or does the dog bring back the object based on the owners voice or gesture？A new study by scientists at Atlantas Emory University seems to indicate that “mans best friend” does indeed know what the owner is saying.The researchers began by asking the owners of twelve dogs of various
17、 kinds to train their pets to identify two toys of different materials，such as a toy animal and a ball.Once the dogs had mastered the task，they took turns inside a special scanner.The owners then tested their dogs language skill by first calling out the names of the toys they had been trained to rec
18、ognize and then saying meaningless words such as“bobbu”and“bodmick”while holding up random objects the dogs hadnt seen before.The scans suggested that the parts of the dogs brains responsible for processing of sounds showed different brain patterns when they heard words they were familiar with，compa
19、red with the ones they had never heard before.While that was not enough to prove that the dogs were picturing their toys when they heard the word，it did indicate some sort of recognition.The researchers believe this is an important step forward in understanding how dogs process language.Even more in
20、teresting was that the dogs brains showed a higher level of neural(神经的)activity at the sound of unknown words.This is the exact opposite of what happens in human brains，which get more active at the sound of familiar words.The researchers say the dogs may become cheerful at the sound of new words to
21、try to understand them in the hope of delighting their masters，“Dogs want to please their owners，and perhaps also receive praise or food，”says Emory neuroscientist Gregory Berns，senior author of the study.However，though your pet may understand human speech，the scientists recommend using visual signa
22、ls and smells for training.“When people want to teach their dogs a trick，they often use spoken command because thats what we humans prefer，”Prichard says.“From the dogs view，however，a visual command might be more effective，helping the dog learn the trick faster.”4Whats the purpose of the new study?A
23、To convince dog owners to understand their dogs.BTo advise dog owners to treat their dogs kindly.CTo prove dogs follow owners order by listening.DTo test out how dogs get information from owners.5What does the author intend to do in Paragraph 2?AInform the result of the research.BState the process o
24、f the research.CStress the importance of the research.DIntroduce the subjects of the research.6How do human brains and dog brains react to words?AHuman brains become active at unfamiliar words.BDog brains become delighted at unfamiliar words.CHuman brains are not sensitive to familiar words.DDog bra
25、ins show no response to familiar words.7What do scientists advise the owners to do in dog training?AGive dogs oral command.BTeach dogs new tricks.CInvolve sight and smell.DEncourage faster learning.【语篇解读】一项关于狗如何对人类语言信号做出反应的科学研究，揭示了狗可以理解人类语言的这一独特之处。4解析：细节理解题。根据文章第一段中的“A new study by scientists.does i
26、ndeed know what the owner is saying.”以及最后一段中的“From the dogs view.helping the dog learn the trick faster.”可知，这一项新研究的目的是测试狗如何获取主人发出的信息，故选D项。答案：D5解析：推理判断题。第二段作者从研究者角度详细阐述了研究步骤，由began，then等词语可知，该段作者的意图是陈述研究过程，故选B项。答案：B6解析：细节理解题。根据第四段中的“Even more interesting was that the dogs brains.This is the exact opp
27、osite of what happens in human brains.familiar words.”可知，人类大脑对熟悉的声音更加敏感、活跃，而与此相反的是，狗对陌生声音更加敏感，故选B项。答案：B7解析：细节理解题。根据文章第五段的“However，though your pet may understand human speech，the scientists recommend using visual signals and smells for training.”可知，科学家建议人们既要使用可视信号，也要使用气味信号来训练狗，故选C项。答案：C.完形填空The stage
28、 lights dimmed，and I took a quick look from behind the heavy black curtains into the audience.Blinded by the lights，I quickly 1 It seems that a great number of eyes were looking at me.I took a deep 2 as the music of my dance began to play.I entered the stage and began my 3 ，the graduation test of th
29、e Indian classical dance.After a decade of learning this art form，I had 4 been considered ready to take on the most difficult act.The test is the most important event in a dancers life，as it pays 5 to all the factors in ones life that 6 the dance form：ones culture and family.The performance is under
30、taken only by the most 7 and determined students.It is a difficult process that requires much 8 For more than six months，I spent two to three hours every day 9 these dances.Many times，I 10 myself to my physical and mental breaking point，but still I would not stop.I could not give up.There was always
31、 so much more to do and so much more to 11 I 12 a lot about myself in those tiring hours.I learned that I was far too 13 to give up，and I was too proud to prove myself 14 after I had set an unrealistic goal.Even with physical pain and mental 15 ，I forced myself to meet my 16 Even when I was at the e
32、nd of my 17 ，there was always something driving me on，forcing me not to give up.Fortunately，I made it.What I had done 18 the success.It was in those hours that I learned what a dancer 19 is.Those time was evidence that I could 20 something I set out to do.1A.reached out Bset offCpulled back Dbroke a
33、way2A.sleep BbreathCthought Dsorrow3A.career BattemptCresponse Dperformance4A.eventually BeasilyCabsolutely Ddesperately5A.debt BrespectCinterest Dvisit6A.develop BrescueCintroduce Dpromote7A.beautiful BfocusedCintelligent Dconsiderate8A.talent BstrengthCcomprehension Dcommitment9A.recording Bdiscus
34、singCpractising Ddesigning10A.pushed BaddictedCtreated Dapplied11A.forget BnoticeClearn Dresearch12A.discovered BabandonedCcontrolled Dundertook13A.brilliant BbraveCstubborn Ddiscouraged14A.careless BnervousCfrightened Dwrong15A.function BstressClevel Daction16A.budget BdeadlineCexpense Dexpectation
35、17A.limit BpurposeCpreparation Ddestination18A.increased BdeservedCexpanded Dexposed19A.completely BchieflyCoriginally Dtruly20A.change BsupplyCaccomplish Dexplain【语篇解读】本文主要讲述了“我”通过刻苦训练，顺利地通过了舞蹈毕业考试。这次经历让“我”发现了自我，并意识到有些目标看似不切实际，难以企及，但只要用心努力做，也能够完成。1解析：根据下文中的“It seems that a great number of eyes were
36、 looking at me.”和常识可知，作者感觉有很多观众正在看着自己，所以此时的作者应是感到非常紧张，快速往后退了几步。reach out意为“伸出”；set off意为“出发；引起；动身”；pull back意为“退却”；break away意为“脱离出去；离开；甩开”。故选C项。答案：C2解析：根据上文可知，作者很紧张，所以在上台表演之前应该做了一次深呼吸来缓解自己的紧张情绪。take a deep breath意为“深呼吸”。sleep意为“睡觉”；thought意为“思想；想法”；sorrow意为“悲伤；悲痛”。故选B项。答案：B3解析：根据上文中的“the music of m
37、y dance began to play”可知，作者上台之后就开始了表演。career意为“生涯；职业”；attempt意为“企图；试图”；response意为“响应；反应”；performance意为“表演；执行；表现”。故选D项。答案：D4解析：根据设空前的“After a decade of learning”可知，作者经过了十年的学习，终于可以参加这个最难的演出了。eventually意为“最后；终于”；easily意为“容易地；轻易地”；absolutely意为“绝对地；完全地”；desperately意为“绝望地；不顾一切地”。故选A项。答案：A5解析：根据空前的“The tes
38、t is the most important event in a dancers life”可知，这次考试非常重要，因为这次考试是向舞蹈发展中的所有生活因素致敬。pay respect to.意为“向致敬”，符合语境。debt意为“债务；欠款”；interest意为“兴趣；利益”；visit意为“访问；参观”。故选B项。答案：B6解析：根据上下文可知，这次考试是向舞蹈发展中的所有生活因素致敬。develop意为“生长；形成；发展”；rescue意为“营救；援救”；introduce意为“介绍；引进”；promote意为“促进；提升”。故选A项。答案：A7解析：根据语境及设空后的“deter
39、mined students”可知，此处应表示参赛舞者的个人品质。设空处所填词应与determined感情色彩一致。focused意为“专注的”，符合语境。beautiful意为“美丽的”；intelligent意为“有智慧的；聪明的”；considerate意为“体贴的；体谅的”。故选B项。答案：B8解析：根据下文中的“For more than six months，I spend two to three hours every day 9 these dances.”可知，在过去半年多的时间里，作者每天花两到三个小时练习这些舞蹈，所以这是一个艰难的过程，要求大量的投入。commitme
40、nt意为“投入”，符合语境。talent意为“才能；天才”；strength意为“力量；力气”；comprehension意为“理解(力)”。故选D项。答案：D9解析：根据上下文可知，在过去半年多的时间里，作者每天花两到三个小时练习舞蹈。practise意为“练习”，符合语境。record意为“记录；记载”；discuss意为“讨论”；design意为“设计；计划”。故选C项。答案：C10解析：根据设空处后的“to my physical and mental breaking point”和下文可知，很多次作者身体状况和精神状态都达到了极限，但是作者仍没有放弃。push意为“逼迫；推动”，符
41、合语境。addict意为“使沉溺；使上瘾”；treat意为“对待；治疗”；apply意为“申请；应用”。故选A项。答案：A11解析：根据下文中的“I learned that I was far too 13 to give up”可知，作者不能放弃，因为还有很多事情要去做，很多东西要去学。learn意为“学习”，符合语境。forget意为“忘记”；notice意为“注意到”；research意为“研究；探索”。故选C项。答案：C12解析：根据下文内容可知，此处应指在那些让人疲惫不堪的时光里，作者发现了真正的自己。discover意为“发现”；abandon意为“抛弃”；control意为“控
42、制；管理”；undertake意为“承担”。故选A项。答案：A13解析：根据空后的“I was too proud to prove myself”和下文中的“there was always something driving me on，forcing me not to give up”可知，作者很骄傲，并且总有一些事情驱使着作者，迫使作者不放弃，由此可知，作者很固执。stubborn意为“固执的”，符合语境。brilliant意为“杰出的；有才气的”；brave意为“勇敢的”；discouraged意为“灰心的；丧气的”。故选C项。答案：C14解析：根据设空处前的“too proud
43、to prove myself”和设空处后的“after I had set an unrealistic goal”可知，作者太骄傲了以至于在设定一个不现实的目标后并不想证明自己是错误的。careless意为“粗心的”；nervous意为“神经质的；紧张不安的”；frightened意为“害怕的”；wrong意为“错误的”。故选D项。答案：D15解析：根据上文可知，作者给自己设定了一个不切实际的目标，所以此处表示精神上的压力。function意为“功能；作用”；stress意为“压力”；level意为“水平；标准”；action意为“行动；行为”。故选B项。答案：B16解析：根据下文中的“f
44、orcing me not to give up”可知，作者给自己设定了一个不切实际的目标，虽然身体不支，也有很大的精神压力，但是作者坚持不放弃，迫使自己达到预期目标。budget意为“预算”；deadline意为“截止期限；最后期限”；expense意为“花费”；expectation意为“期待；预期；指望”。故选D项。答案：D17解析：根据上文中的“physical and mental breaking point”可知，此处应指作者达到了自己极限的尽头。limit意为“限制；限度；界限”；purpose意为“目的”；preparation意为“预备；准备”；destination意为“
45、目的地；终点”。故选A项。答案：A18解析：根据上文中的“Fortunately，I made it.”可知，作者最终成功了，设空处应表示作者所做的一切都值了。increase意为“增加；增长”；deserve意为“应受到；应得”；expand意为“扩张；使膨胀”；expose意为“显露；揭发”。故选B项。答案：B19解析：结合全文可知，是那些艰难的时光让作者明白了一位真正的舞者是什么样子的。completely意为“完全地；彻底地”；chiefly意为“主要地”；originally意为“最初；起初”；truly“真实地”。故选D项。答案：D20解析：结合全文可知，作者设定了一个不切实际的目标，但最终完成了它，那段时光也成为作者能够完成自己计划去做的事情的见证。change意为“改变”；supply意为“供给；提供”；accomplish意为“完成；实现”；explain意为“说明；解释”。故选C项。答案：C
