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1、Toefl iBT Practice Test TPO 10 Reading Section 2No. of Questions: 28Time: 40 minutesBegin Test10If you cannot see the timer or if you cannot set the timer, youll need to install flash player. Click here to download and install adobe flash player.Set the timer to “40:00” before doing the test.Variati

2、ons in the ClimateOne of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities is that it is hard to get a measure of what constitutes the natural variability of the climate. We know that over the past millennia the climate has under

3、gone major changes without any significant human intervention.We also know that the global climate system is immensely complicated and that everything is in some way connected, and so the system is capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of

4、its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human activities.Instrumental records do not go back far enough to provide us with reliable measurements of global climatic variability on timescales longer than a ce

5、ntury. What we do know is that as we include longer time intervals, the record shows increasing evidence of slow swings in climate between different regimes. To build up a better picture of fluctuations appreciably further back in time requires us to use proxy records.Over long periods of time, subs

6、tances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of changes in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, henc

7、e the observed changes in the records can be dated. Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out

8、of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that

9、 temperature10Question 1 of 28According to paragraph 1, which of the following must we find out in order to determine the impact of human activities upon climate?The major changes in climate over the past millenniaThe degree to which the climate varies naturallyThe best method for measuring climatic

10、 changeThe millennium when humans began tointerfere with the climateParagraph 1 is marked with Variations in the Climate One of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities is that it is hard to get a measure of what constit

11、utes the natural variability of the climate. We know that over the past millennia the climate has undergone major changes without any significant human intervention. We also know that the global climate system is immensely complicated and that everything is in some way connected, and so the system i

12、s capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human activities.Instrumental records do not go back far enoug

13、h to provide us with reliable measurements of global climatic variability on timescales longer than a century. What we do know is that as we include longer time intervals, the record shows increasing evidence of slow swings in climate between different regimes. To build up a better picture of fluctu

14、ations appreciably further back in time requires us to use proxy records.Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of changes in those properties overtim

15、e, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usually

16、 referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers

17、, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature10Question 2 of 28According to paragraph 2, an advantage of proxy records over instrumental records is thatthey are more-reliable measures of climatic variability in the past centuryth

18、ey provide more-accurate measures of local temperaturesthey provide information on climate fluctuations further back in timethey reveal information about the human impact on the climateParagraph 2 is marked with Variations in the ClimateOne of the most difficult aspects of deciding whether current c

19、limatic events reveal evidence of the impact of human activities is that it is hard to get a measure of what constitutes the natural variability of the climate. We know that over the past millennia the climate has undergone major changes without any significant human intervention.We also know that t

20、he global climate system is immensely complicated and that everything is in some way connected, and so the system is capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent c

21、hanges are natural as opposed to being the result of human activities. Instrumental records do not go back far enough to provide us with reliable measurements of global climatic variability on timescales longer than a century. What we do know is that as we include longer time intervals, the record s

22、hows increasing evidence of slow swings in climate between different regimes. To build up a better picture of fluctuations appreciably further back in time requires us to use proxy records.Over long periods of time, substances whose physical and chemical properties change with the ambient climate at

23、 the time can be deposited in a systematic way to provide a continuous record of changes in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature,

24、rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sedime

25、nts in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature10Question 3 of 28Which of the sentences below best expresses the es

26、sential information in the 【highlighted sentence】in the passage? Incorrect choices change the meaning in important ways or leave out essential informationBecause physical and chemical properties of substances are unchanging, they are useful records of climate fluctuations over timeFor hundreds or th

27、ousands of years, people have been observing changes in the chemical and physical properties of substances in order to infer climate changeBecause it takes long periods of time for the climate to change, systematic changes in the properties of substances are difficult to observe.Changes in systemati

28、cally deposited substances that are affected by climate can indicate climate variations over time.Variations in the ClimateOne of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities is that it is hard to get a measure of what const

29、itutes the natural variability of the climate. We know that over the past millennia the climate has undergone major changes without any significant human intervention.We also know that the global climate system is immensely complicated and that everything is in some way connected, and so the system

30、is capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human activities.Instrumental records do not go back far enou

31、gh to provide us with reliable measurements of global climatic variability on timescales longer than a century. What we do know is that as we include longer time intervals, the record shows increasing evidence of slow swings in climate between different regimes. To build up a better picture of fluct

32、uations appreciably further back in time requires us to use proxy records.【 Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of changes in those properties over

33、time, sometimes for hundreds or thousands of years. 】 Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated.Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usu

34、ally referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glac

35、iers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature10Question 4 of 28According to paragraph 3, scientists are able to reconstruct proxy temperature records bystudying regional differences in temperature variationsstudying and datin

36、g changes in the properties of substancesobserving changes in present day climate conditionsinferring past climate shifts from observations of current climatic changesParagraph 3 is marked with Variations in the ClimateOne of the most difficult aspects of deciding whether current climatic events rev

37、eal evidence of the impact of human activities is that it is hard to get a measure of what constitutes the natural variability of the climate. We know that over the past millennia the climate has undergone major changes without any significant human intervention.We also know that the global climate

38、system is immensely complicated and that everything is in some way connected, and so the system is capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural

39、 as opposed to being the result of human activities.Instrumental records do not go back far enough to provide us with reliable measurements of global climatic variability on timescales longer than a century. What we do know is that as we include longer time intervals, the record shows increasing evi

40、dence of slow swings in climate between different regimes. To build up a better picture of fluctuations appreciably further back in time requires us to use proxy records. Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be d

41、eposited in a systematic way to provide a continuous record of changes in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature, rainfall, and othe

42、r aspects of the climate that can be inferred from the systematic changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Eur

43、ope, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature10Question 5 of 28The word 【striking】 in the passage is closest in meaning tonoticeabl

44、e confusing trueunlikelyVariations in the ClimateOne of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities is that it is hard to get a measure of what constitutes the natural variability of the climate. We know that over the past

45、millennia the climate has undergone major changes without any significant human intervention.We also know that the global climate system is immensely complicated and that everything is in some way connected, and so the system is capable of fluctuating in unexpected ways. We need therefore to know ho

46、w much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human activities.Instrumental records do not go back far enough to provide us with reliable measurements of global climatic variability

47、 on timescales longer than a century. What we do know is that as we include longer time intervals, the record shows increasing evidence of slow swings in climate between different regimes. To build up a better picture of fluctuations appreciably further back in time requires us to use proxy records.

48、Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of changes in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering

49、occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstru

50、cted from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broa

51、dly consistent indications that temperature10Question 6 of 28According to paragraphs 3 and 4, proxy data have suggested all of the following about the climate EXCEPT:Regional climates may change overtime.The climate has changed very little in the past10.000 years.Global temperatures vary more than r

52、egional temperatures.Important natural changes in climate have occurred over large timescales.Paragraphs 3 and 4 are marked with Variations in the ClimateOne of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities is that it is hard

53、 to get a measure of what constitutes the natural variability of the climate. We know that over the past millennia the climate has undergone major changes without any significant human intervention.We also know that the global climate system is immensely complicated and that everything is in some wa

54、y connected, and so the system is capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human activities.Instrumental

55、records do not go back far enough to provide us with reliable measurements of global climatic variability on timescales longer than a century. What we do know is that as we include longer time intervals, the record shows increasing evidence of slow swings in climate between different regimes. To bui

56、ld up a better picture of fluctuations appreciably further back in time requires us to use proxy records. Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of ch

57、anges in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic

58、 changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature10Question 7 of 28The word 【erratic】 in the passage is closest in meaning todramatic important unpredictablecom