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1、 为了帮助大家高效备考托福， 为大家带来托福 TPO45 阅读 Passage1 原文文本+题目+答案 解析，希望对大家备考有所帮助。 Microscopes The Beringia Landscape During the peak of the last ice age,northeast Asia(Siberia)and Alaska were connected by a broad land mass called the Bering Land Bridge.This land bridge existed because so much of Earths water was
2、frozen in the great ice sheets that sea levels were over 100 meters lower than they are today.Between 25,000 and 10,000 years ago,Siberia,the Bering Land Bridge,and Alaska shared many environmental characteristics.These included a common mammalian fauna of large mammals,a common flora composed of br
3、oad grasslands as well as wind-swept dunes and tundra,and a common climate with cold,dry winters and somewhat warmer没有 wanner 这个单词和 summer 搭配 哈，我觉得应该是转码故障导致的问题，应该是 warmer。summers.The recognition that many aspects of the modem flora and fauna were present on both sides of the Bering Sea as remnants o
4、f the ice-age landscape led to this region being named Beringia. It is through Beringia that small groups of large mammal hunters,slowly expanding their hunting territories,eventually colonized North and South America.On this archaeologists generally agree,but that is where the agreement stops.One b
5、road area of disagreement in explaining the peopling of the Americas is the domain of paleoecologists,but it is critical to understanding human history:what was Beringia like? The Beringian landscape was very different from what it is today. A Broad,windswept valleys;glaciated mountains;sparse veget
6、ation;and less moisture created a rather forbidding land mass.B This land mass supported herds of now- extinct species of mammoth,bison,and horse and somewhat modern versions of caribou,musk ox,elk,and saiga antelope.C These grazers supported in turn a number of impressive carnivores,including the g
7、iant short-faced bear,the saber-tooth cat,and a large species of lion.D The presence of mammal species that require grassland vegetation has led Arctic biologist Dale Guthrie to argue that while cold and dry,there must have been broad areas of dense vegetation to support herds of mammoth,horse,and b
8、ison.Further,nearly all of the ice-age fauna had teeth that indicate an adaptation to grasses and sedges;they could not have been supported by a modern flora of mosses and lichens.Guthrie has also demonstrated that the landscape must have been subject to intense and continuous winds,especially in wi
9、nter.He makes this argument based on the anatomy of horse and bison,which do not have the ability to search for food through deep snow cover.They need landscapes with strong winds that remove the winter snows,exposing the dry grasses beneath.Guthrie applied the term“mammoth steppe“to characterize th
10、is landscape. In contrast,Paul Colinvaux has offered a counterargument based on the analysis of pollen in lake sediments dating to the last ice age.He found that the amount of pollen recovered in these sediments is so low that the Beringian landscape during the peak of the last glaciation was more l
11、ikely to have been what he termed a“polar desert,“with little or only sparse vegetation,in no way was it possible that this region could have supported large herds of mammals and thus,human hunters.Guthrie has argued against this view by pointing out that radiocarbon analysis of mammoth,horse,and bi
12、son bones from Beringian deposits revealed that the bones date to the period of most intense glaciation. The argument seemed to be at a standstill until a number of recent studies resulted in a spectacular suite of new finds.The first was the discovery of a 1,000-square- kilometer preserved patch of
13、 Beringian vegetation dating to just over 17,000 years agothe peak of the last ice age.The plants were preserved under a thick ash fall from a volcanic eruption.Investigations of the plants found grasses,sedges,mosses,and many other varieties in a nearly continuous cover,as was predicted by Guthrie.
14、But this vegetation had a thin root mat with no soil formation,demonstrating that there was little long-term stability in plant cover,a finding supporting some of the arguments of Colinvaux.A mixture of continuous but thin vegetation supporting herds of large mammals is one that seems plausible and
15、realistic with the available data. Paragraph 1 During the peak of the last ice age,northeast Asia(Siberia)and Alaska were connected by a broad land mass called the Bering Land Bridge.This land bridge existed because so much of Earths water was frozen in the great ice sheets that sea levels were over
16、 100 meters lower than they are today.Between 25,000 and 10,000 years ago,Siberia,the Bering Land Bridge,and Alaska shared many environmental characteristics.These included a common mammalian fauna of large mammals,a common flora composed of broad grasslands as well as wind-swept dunes and tundra,an
17、d a common climate with cold,dry winters and somewhat warmer summers.The recognition that many aspects of the modem flora and fauna were present on both sides of the Bering Sea as remnants of the ice-age landscape led to this region being named Beringia. 1.The word“remnants“in paragraph 1is closest
18、in meaning to A.remains B.evidence C.results D.reminders Paragraph 2 It is through Beringia that small groups of large mammal hunters,slowly expanding their hunting territories,eventually colonized North and South America.On this archaeologists generally agree,but that is where the agreement stops.O
19、ne broad area of disagreement in explaining the peopling of the Americas is the domain of paleoecologists,but it is critical to understanding human history:what was Beringia like? 2.The word“domain“in paragraph 2 is closest in meaning to A.field of expertise B.challenge C.interest D.responsibility P
20、aragraph 3 The Beringian landscape was very different from what it is today. A Broad,windswept valleys;glaciated mountains;sparse vegetation;and less moisture created a rather forbidding land mass.B This land mass supported herds of now- extinct species of mammoth,bison,and horse and somewhat modern
21、 versions of caribou,musk ox,elk,and saiga antelope.C These grazers supported in turn a number of impressive carnivores,including the giant short-faced bear,the saber-tooth cat,and a large species of lion.D 3.According to paragraph 3,all of the following are true of the Beringian landscape EXCEPT A.
22、There was little vegetation. B.The mammal species there all survived into modern versions. C.The climate was drier than it is today. D.There were mountains with glaciers. 4.The purpose of paragraph 3 is to A.contrast todays Beringian landscape with other landscapes in the American continent B.descri
23、be the Beringian landscape during the last ice age C.explain why so many Beringian species became extinct during the last ice age D.summarize the information about Beringia that historians agree on Paragraph 4 The presence of mammal species that require grassland vegetation has led Arctic biologist
24、Dale Guthrie to argue that while cold and dry,there must have been broad areas of dense vegetation to support herds of mammoth,horse,and bison.Further,nearly all of the ice-age fauna had teeth that indicate an adaptation to grasses and sedges;they could not have been supported by a modern flora of m
25、osses and lichens.Guthrie has also demonstrated that the landscape must have been subject to intense and continuous winds,especially in winter.He makes this argument based on the anatomy of horse and bison,which do not have the ability to search for food through deep snow cover.They need landscapes
26、with strong winds that remove the winter snows,exposing the dry grasses beneath.Guthrie applied the term“mammoth steppe“to characterize this landscape. 5.The word“continuous”in paragraph 4 is closest in meaning to A.unpredictable B.very cold C.dangerous D.uninterrupted 6.Which of the sentences below
27、 best expresses the essential information in the highlighted sentence in the passage?Incorrect choices change the meaning in important ways or leave out essential information. A.According to biologist Dale Guthrie,mammal species require broad areas of vegetation to survive. B.Dale Guthrie is an Arct
28、ic biologist who argued that broad areas of dense vegetation were surely enough to attract mammals such as mammoth,horse,and bison to Beringia. C.Dale Guthrie argued that Beringia,though cold and dry,must have had enough dense vegetation to support the herds of mammoth,horse,and bison that lived the
29、re. D.As long as Beringia was cold and dry,argued Dale Guthrie,dense vegetation grew in order to support the herds of mammoth,horse,and bisonthe mammal species present there. 7.According to paragraph 4,Guthrie believes that the teeth of ice-age fauna support which of the following conclusions? A.Lar
30、ge mammals would not have been able to survive in the Beringian landscape. B.Grasslands were part of the Beringian landscape. C.Strong winds exposed dry grasses under the snow. D.Horses and bison did not have the ability to search for food through deep snow cover. 8.According to paragraph 4,which of
31、 the following statements is true of the relationship between ice-age Beringian animals and their environment? A.When present in sufficient quantities,lichens and mosses provide enough nutrients to satisfy the needs of herds of large mammals. B.The anatomy of certain animals present in that environm
32、ent provides information about the intensity of winds there at that time. C.The structure of the teeth of most ice-age fauna indicates that they preyed on animals such as the mammoth,horse,and bison. D.Horses and bison are large enough that their feet can easily penetrate deep snow and uncover areas
33、 where they can feed on plant material. Paragraph 5 In contrast,Paul Colinvaux has offered a counterargument based on the analysis of pollen in lake sediments dating to the last ice age.He found that the amount of pollen recovered in these sediments is so low that the Beringian landscape during the
34、peak of the last glaciation was more likely to have been what he termed a“polar desert,“with little or only sparse vegetation,in no way was it possible that this region could have supported large herds of mammals and thus,human hunters.Guthrie has argued against this view by pointing out that radioc
35、arbon analysis of mammoth,horse,and bison bones from Beringian deposits revealed that the bones date to the period of most intense glaciation. 9.In paragraph 5,the amount of pollen in Beringian lake sediments from the last ice age is used to explain A.how long the ice age lasted B.how important poll
36、en is as a source of food C.how many different kinds of plants produce pollen D.how little vegetation must have been present at that time 10.According to paragraph 5,how did Dale Guthrie use the information about radiocarbon analysis of bones from Beringian deposits? A.To suggest that Colinvaux shou
37、ld have used different methods to measure the amount of pollen in ice-age lake sediments B.To argue that the large Beringian mammals must have eaten plants that produce little,if any,pollen C.To show that the conclusions that Colinvaux drew from the analysis of pollen in ice-age lake sediments canno
38、t be correct D.To explain why so-called polar deserts are incapable of supporting such large animals as mammoth,horse,and bison Paragraph 6 The argument seemed to be at a standstill until a number of recent studies resulted in a spectacular suite of new finds.The first was the discovery of a 1,000-s
39、quare- kilometer preserved patch of Beringian vegetation dating to just over 17,000 years agothe peak of the last ice age.The plants were preserved under a thick ash fall from a volcanic eruption.Investigations of the plants found grasses,sedges,mosses,and many other varieties in a nearly continuous
40、 cover,as was predicted by Guthrie.But this vegetation had a thin root mat with no soil formation,demonstrating that there was little long-term stability in plant cover,a finding supporting some of the arguments of Colinvaux.A mixture of continuous but thin vegetation supporting herds of large mamma
41、ls is one that seems plausible and realistic with the available data. 11.The word“plausible“in the paragraph 6 is closest in meaning to A.preferable B.practical C.reasonable D.advantageous 12.Which of the following best describes the organization of paragraph 6? A.Two contrasting views are presented
42、,and a study that could decide between them is proposed B.An argument is offered,and reasons both for and against the argument are presented C.A claim is made,and a study supporting the claim is described D.New information is presented,and the information is used to show that two competing explanati
43、ons can each be seen as correct in some way. 13.Look at the four squaresthat indicate where the following sentence could be added to the passage. Nevertheless,large animals managed to survive in Beringia. Where would the sentence best fit?Click on a squareto add the sentence to the passage. 14.Direc
44、tions: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 pas
45、sage or are minor ideas in the passage.This question is worth 2 points. Drag your answer choices to the spaces where they belong.To remove an answer choice,click on it. To review the passage,click VIEW TEXT During the last ice age,human hunters pursued large mammals across Beringia,a land whose clim
46、atic characteristics have been in dispute. Answer Choices A.Strong evidence indicates that large mammals like mammoth and bison survived in the harsh ice-age Beringian landscape. B.Carnivores such as the saber-tooth cat were primarily responsible for the disappearance of the largest of the grazing a
47、nimals,but the harsh winters caused some grazers to die of starvation. C.The discovery that grasses,sedges,and mosses survived under the thick ash from a large volcanic eruption proved that the ice-age Beringian plant cover was extremely resistant to climatic extremes. D.Beringian mammals crossed ea
48、sily from northeastern Asia to Alaska across the Bering Land Bridge,though there are indications that they usually went back to Asia for the brief,but warm,summers. E.Analyses of ice-age sediments uncovered very small amounts of pollen,suggesting that Beringia lacked the quantity of vegetation neede
49、d to support large herds of mammals. F.Recent discoveries suggest that shallow-rooted plants created a fairly continuous cover over ice-age Beringia,though the cover most likely was variable and uncertain in any one location. 参考译文 微观白令陆桥地貌 在最后一次冰河世纪的顶峰期，亚洲的东北部(西伯利亚)和阿拉斯加是由一片巨大的陆 地连接在一起，这个地区叫白令陆桥。白令陆桥出现的原因是，地球上大量海水被冻住，形 成大片冰川，使得海平面比今天要低 100 米。在 2 万 5 千到 1 万年前之间的这段时间，西伯 利亚、白令陆桥和阿拉斯加有着很多相似的环境特征。比如，很多大型哺乳动物，广阔的草 原及其中的各种植物，多风的沙丘和冻土，寒冷干燥的冬天和炎热的夏季。人们发现很多现 代动植物的特征在白令海两侧都存在，其实就是冰河时期地貌遗留下来的，所以，这个地区 被命名为白令陆桥。 一群群的狩猎大型动物的猎人，穿过白令陆桥，逐渐扩张他们捕猎的地区，最终迁徙并 居住在北美和南美洲。考古学家通常同意这个观点，但也就仅仅同意这个观点而