北美新托福入学测试题中上水平.docx

1、北美新托福入学测试题中上水平环球新托福考试院入学英语水平测试题Read ingExtin cti on of the Dino saursPale on tologists have argued for a long time that the demise of the dino saurs was caused by climatic alterati ons associated with slow cha nges in the positi ons of continents and seas result ing from plate tectonics. Off and on

2、throughout the Cretaceous (the last period of the Mesozoic era, during which/ dino saurs flourished), large shallow seas covered exte nsive areas of the continen ts. Data from diverse sources, in cludi ng geochemical evide nee preserved in seafloor sedime nts, in dicate that the LateCretaceous clima

3、te was milder than today s. The days were not too hot, nor the nights too cold. Thesummers were not too warm, nor the winters too frigid. The shallow seas on the continents probably buffered the temperature of the n earby air, keep ing it relatively con sta nt.At the end of the Cretaceous, the geolo

4、gical record shows that these seaways retreated from the continents back into the major ocean basins. No one knows why. Over a period of about 100,000 years, while the seas pulled back, climates around the world became dramatically more extreme: warmer days, cooler nights; hotter summers, colder win

5、ters. Perhaps dinosaurs could not tolerate these extremetemperature cha nges and became ext inct.weres hard to un dersta nd why tweyld not be affected, whereasdinosaurs were left too crippled to cope, especially if, as some scientists believe, dinosaurswarm-blooded. Critics also point out that the s

6、hallow seaways had retreated from and adva need on the continents numerous times during the Mesozoic, so why did the dinosaurs survive the climatic changesappeali ng, theassociated with the earlier fluctuations but not with this one? Although initially hypothesis of a simple climatic cha nge related

7、 to sea levels is in sufficie nt to expla in all the data.Dissatisfact ion with conven ti onal expla nati ons for dino saur ext in cti ons led /to a surpris ingobservation that, in turn, has suggested a new hypothesis. Many plants and animals disappearabruptly from the fossil record as one moves fro

8、m layers of rock docume nting the end of the Cretaceous up into rocks represe nting the beg inning of the Ceno zoic (the era after the Mesozoic). Betwee n the last layer of Cretaceous rock and the first layer of Cenozoic rock, there is often a thin layer of clay. Scientists felt that they could get

9、an idea of how long the ext inctions took by determ ining how long it took to deposit this one centimeter of clay and they thought they could determine the time it took to deposit the clay by determ ining the amount of the eleme nt iridium (lr) it contain ed.s history. Becaus，s core as thIt has not

10、bee n com mon at Earth s since the very begi nning of the pla netusually exists in a metallic state, it was preferentially incorporated in Earth and consolidated. lt is found in high concentrations in some meteorites, in which the solar systemorigi nal chemical compositi on is preserved. Even today,

11、 microscopic meteorites con ti nu ally bombard Earth, falling on both land and sea. By measuring how many of these meteorites fall to Earth over a given period of time, scientists can estimate how long it might have taken to deposit the observedamount of it in the boundary clay. These calculations s

12、uggest that a period of about one million yearswould have been required. However, other reliable evidenee suggests that the deposition of theboundary clay could not have taken one million years. So the unusually high concentration of lt seemsto require a special expla nati on.In view of these facts,

13、 scie ntists hypothesized that a sin gle large asteroid, about 10 to 15 kilometersacross, collided with Earth, and the resulting fallout created the boundary clay. Their calculationsshow that the impact kicked up a dust cloud that cut off sun light for several mon ths, in hibit ingphotosynthesis in

14、plants; decreased surface temperatures on continents to below freezing; causedextreme episodes of acid rain; and significantly raised Iong-term global temperatures through thegree nhouse effect. This disrupti on of food cha in and climate would have eradicated the dino saurs andother orga ni sms in

15、less tha n fifty years.Passage EndQuesti onParagraph 1 Paleontologists have argued for a long time that the demise of the dinosaurs wascaused by climatic alterati ons associated with slow cha nges in the positi ons of con ti nents and seasresult ing from plate tect oni cs. Off and on throughout the

16、Cretaceous (the last period of the Mesozoic era, duri ng which dino saurs flourished), large shallow seas covered exte nsive areas of the con ti nen ts. Data from diverse sources, in clud ing geochemical evide nee preserved in seafloor sedime nts, in dicate that theLate Cretaceous climate was milder

17、 than today s. The days were not too hot, nor the nights too cold.The summers were not too warm, nor the winters too frigid. The shallow seas on the continents probably buffered the temperature of the n earby air, keep ing it relatively con sta nt.1.According to paragraph 1, which of the following i

18、s true of the Late Cretaceous climate?Summers were very warm and win ters were very cold.Shallow seas on the con ti nents caused freque nt temperature cha nges.The climate was very similar to today s climate.The climate did not cha nge dramatically from seas on to seas on.Paragraph 2 At the end of t

19、he Cretaceous, the geological record shows that these seaways retreatedfrom the continents back into the major ocean basins. No one knows why. Over a period of about 100,000 years, while the seas pulled back, climates around the world became dramatically more extreme: warmer days, cooler ni ghts; ho

20、tter summers, colder win ters. Perhaps dino saurs could nottolerate these extreme temperature cha nges and became ext inct.2.Which of the follow ing reas ons is suggested in paragraph 2 for the ext inction of the dino saurs?Changes in the lengths of the days and nights during the late Cretaceous per

21、iodDroughts caused by the moveme nt of seaways back into the ocea nsThe cha nge from mild to severe climates duri ng the Late Cretaceous periodAn extreme decrease in the average yearly temperature over 10,000 yearsParagraph 3 If true, though, why did cold-blooded ani mals such as sn akes, lizards, t

22、urtles, andcrocodiles survive the freezing winters and torrid summers? These animals are at the mercy of theclimate to maintain a livable body temperature. It shard to understand why they would not beaffected, whereas dinosaurs were left too crippled to cope, especially if, as some scientists believ

23、e,dino saurs were warm-blooded. Critics also point out that the shallow seaways had retreated from and advaneed on the continents numerous times during the Mesozoic, so why did the dinosaurs survive the climatic changes associated with the earlier fluctuations but not with this one? Although initial

24、lyappealing, the hypothesis of a simple climatic change related to sea levels is insufficient to explain all the data.3.Why does the author mention the survival of “ snakes, lizards, turtles, and crocodiles ”nparagraph 3?To argue that dino saurs may have become exti net because they were not cold-bl

25、ooded ani malsTo questi on the adequacy of the hypothesis that climatic cha nge related to sea levels caused theext inction of the dino saursTo prese nt examples of ani mals that could maintain a livable body temperature more easily tha ndino saursTo support a hypothesis that these animals were not

26、as sensitive to climate changes in theCretaceous period as they are today4.The word cope in the passage is closest in meaning toad aptmovecon ti nuecompete5.The word fluctuati ons in the passage is closest i n meaning toextremesretreats periods variati onsParagraph 4 Dissatisfacti on with conven tio

27、 nal expla nati ons for dino saur ext in cti ons led to asurprising observation that, in turn, has suggested a new hypothesis. Many plants and animalsdisappear abruptly from the fossil record as one moves from layers of rock docume nti ng the end of the Cretaceous up into rocks representing the begi

28、nning of the Cenozoic (the era after the Mesozoic). Between the last layer of Cretaceous rock and the first layer of Cenozoic rock, there is often a thin layer of clay. Scientists felt that they could get an idea of how long the extinctions took by determining how long it took to deposit this one ce

29、ntimeter of clay and they thought they could determine the time it took to deposit the clay by determ ining the amount of the eleme nt iridium it contain ed.6.Which of the sentences below best expresses the essential information in the highlightedsentence in the passage? In correct choices change th

30、e meaning in important ways or leave outesse ntial in formati on.The fossil record suggests that there was an abrupt ext in cti on of many pla nts and ani mals at theend of the Mesozoic era.Few fossils of the Mesozoic era have survived in the rocks that mark the end of the Cretaceous.Fossils from th

31、e Cretaceous period of the Mesozoic up to the begi nning of the Ceno zoic era havebee n removed from the layers of rock that surroun ded them.Pla nts and ani mals from the Mesozoic era were un able to survive in the Ceno zoic era.7.I n paragraph 4, all the followi ng questi ons are an swered EXCEPT:

32、Why is there a layer of clay betwee n the rocks of the Cretaceous and Ceno zoic?Why were scientists interested in determining how long it took to deposit the layer of clay at the endof the Cretaceous?What was the effect of the surpris ing observati on scie ntists made?Why did scie ntists want more in formati on about the dino saur ext in cti ons at the end of theCretaceous?Paragraph 5. lt has not bee n com mon at Earth s since the very begi nning of the pla net sBecause