托福TPO49三篇阅读答案之第一篇：Ancient Coastlines
1. The word "crucial" in the passage is closest in meaning to【词汇题】
A.Interesting
B.Important
C.Established
D.Understood
答案：B
解析：
crucial:至关重要的 。a是有趣的，b是重要的，c是建立的，d是理解的。综合选项，b最符合。
2.Which of the sentences below 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.【句子简化题】
A.In the last few centuries,the erosion of coastline created the Neolithic stone circle in Brittany,France,at the same time that it destroyed the medieval villages in Yorkshire,England.
B.Coastlines have changed even in recent times as shown by the current locations of certain Neolithic monuments and medieval villages.
C.Recent changes in the coastlines near the Neolithic stone circle of Er Lannic in Brittany,France,and the medieval villages in Yorkshire,England,suggest that ancient coastlines changed in similar ways.
D.Changes in coastlines can lead to the creation of islands such as Er Lannic in France or the total erosion of the cliffs as in Yorkshire in England,though no considerable changes have occurred in recent periods.
答案：B
解析：
提取句子主干，将括号和从句里的内容先去掉，则句子为These have changed constantly through time,even in relatively recent periods,as can be seen from the Neolithic stone circle of Er Lannic,in Brittany,France or medieval villages in east Yorkshire,England。主语these指代前一句的ancient coastlines。句子主干的大意为“海岸线始终在改变，即使在最近的时期，这一现象可以通过Neolithic stone circle和 medieval villages看出“。b选项是对原句的同义替换表达，故正确。a选项的两个谓语动作，即created和destroyed原句中均未提及。c选项说recent coastline changes和ancient coastline changes改变的方式一样，原句未提及。d选项的lead to因果关系在原句中没有体现。
3. According to paragraph 1,the city of Ephesus in western Turkey is an example of which of the following?
A.Recent changes in the shoreline that have resulted in the creation of new land.
B.Port cities that have lost shoreline due to the erosion of land.
C.The ocean's role in the formation of new land.
D.The importance of changes in shoreline to cities located inland.
答案：A
解析：
题干问Ephesus in western Turkey是以下哪项的例子。通过题干的Ephesus in western Turkey定位至原文最后一句话的后半部分，由as可以看出，答案为前半句。“silts deposited by rivers sometimes push the sea farther back,creating new land”，同义改写之后即为a。
4.Which of the following can be inferred from paragraph 2 about the effects of climate change during the Paleolithic period?【推断题】
A.The amount of land not covered by water was a greater during warmer periods.
B.Warmer weather encouraged the expansion of the range of flora and fauna.
C.As a result of colder weather,land bridges became exposed.
D.The rise of sea level occurred during periods of cold weather.
答案：C
解析：
综合本段第3句和第4句，“When the ice sheets grew,the sea level would drop” ，当冰原增大的时候，海平面会下降;“Falls in sea level often exposed a number of important land bridges”，海平面的下降通常会暴露出大量重要的陆桥。得出推理：冰原增大是由于低温，故低温会导致陆桥显现。
5.By indicating that flora and fauna of isolated or insular areas were often irreversibly affected by the changes due to the Ice Age,the author means that the flora and fauna were.【推断题】
A.Unable to return to their previous conditions.
B.In a constant state of change.
C.Completely destroyed by human colonization
D.Unevenly distributed across the area.
答案：A
解析：
本题可以从短语本身着手。irreversibly affected意为“不可逆转地受到了影响“，植物和动物受到了影响即发生了改变，不可逆转即无法回到改变之前的状态，故答案为d。
6.According to paragraph 2,all of the following are true of Beringia EXCEPT:【选择是非题】
A.It may have been used by the people who first colonized North America.
B.It may have been large enough to support life.
C.It was probably still four meters under water during the glacier maximum.
D.It was probably a vast plain.
答案：C
解析：
根据题干的Beringia定位至本段倒数第二句话，故确定答案范围在最后两句话中。a选项对应原文最后一句话，The existence of Beringia…the New World，故排除;b选项对应倒数第二句的1,000 kilometers from the north to the south和最后一句的the extent to which it could have supported human life，排除;原文倒数第二句提到在glacier maximum的期间，海平面下降了120米，露出了一个大平原，即Beringia,也就是说Beringia位于海平面之上，与c选项的仍旧在水面以下4米表述冲突，故c为正确答案;故d选项对应倒数第二句的which therefore created not merely a bridge but a vast plain，排除。
7.What purpose does the discussion about the Bering Strait in paragraph 2 serve in the passage?【目的题】
A.It explains the idea that changes in coastlines do not necessarily result in significant alternations to existing marine life.
B.It illustrates the kind of impact that variations in land availability caused by climate change can have.
C.It provides a large amount of archaeological evidence that casts doubt on changes in sea level during the Paleolithic period.
D.It shows how ancient coastlines can serve as useful models in understanding recent changes in coastlines.
答案：B
解析：
通过题干的Bering Strait定位至本段第5句话，提到具体的白令海峡是一个例子，故往前看。前一句提到温度变低导致海平面下降，海平面下降使得陆桥出现。例子本身说的是海平面下降暴露出了白令海峡，例子和前句观点所表达的意思一样，即例子是为了说明温度变化对land availability的影响。答案为b。
8.The word "remnants" in the passage is closest meaning to【词汇题】
A.Remains
B.Regions
C.Points
D.Origins
答案：A
解析：
remnant：剩余部分，残余。a是遗留，b是地区，c是地点，d是起源。综合选项为a。
9.According to paragraph 3,why is the height of a raised beach not a straightforward indicator of past sea level?【细节题】
A.The height of the beach may have been raised or altered by human interventions in the shore environment.
B.The height of the beach may be the result of erosion over a brief period of time.
C.It is difficult to assess if the sea actually existed at that level for any significant period of time.
D.The surface of Earth may have shifted,moving the beach from its original positron.
答案：D
解析：
通过题干定位至本段第3句，题干问原因，故答案一般位于后一句话。“In the majority of cases,the beaches lie at a higher level because the land has been raised up through isostatic uplift or tectonic movement.”，概括原因为陆地的变化导致了沙滩的的位置变化，故答案为d。
10.According to paragraph 3,which of following causes an isostatic uplift?【细节题】
A.Shifts in Earth's crust.
B.A decrease in the pressure of thick ice sheets.
C.A decrease in temperature.
D.Changes in sea level.
答案：B
解析：
通过题干定位至本段第5句，Isostatic uplift of the land occurs when the weight of ice is removed as temperatures rise，即随着温度升高，冰块重量减轻，因此产生了isostatic uplift，核对选项，b为原文的同义改写，故正确。
11.The word "comprising" in the passage 4 is closest in meaning to【词汇题】
A.Taken from
B.Made up of
C.Suggesting
D.Covering
答案：B
解析：
comprising：组成。a是降低，b是组成，c是暗示/表面，d是覆盖。综合选项，b为正确答案。
12.Which of the following can be inferred from paragraph 4 about Tokyo Bay?【推断题】
A.The coastal land currently available is smaller than it was during the Japan period.
B.The height of raised beaches around Tokyo Bay is a poor indicator of ancient sea levels.
C.The water temperature in Tokyo Bay is lower at present than it was during the Jomon period.
D.Tectonic movement during the Jomon period was not responsible for the formation of Tokyo Bay's raised beaches.
答案：C
解析：
本段第二句话提到Tokyo Bay是Jomon时期的shell mounds，最后一句话又提到分析贝类本身可以证实海洋地形的变化，因为只有在海水淹没的最高值阶段才会存在亚热带的软体动物，这暗示着更高的水温。(Analysis of the shells themselves has confirmed the changes in marine topography,for it is only during the maximum phase that subtropical species of mollusc are present,indicating a higher water temperature.)推理：软体动物的存在暗示着水温高，而Tokyo Bay是Jomon时期由软体动物组成的贝冢，故可以推出Tokyo Bay的水温在Jomon时期要比现在高。故答案为c。
13.The location of these heaps of rubbish can be an accurate indicator of earlier coastlines.【插入题】
答案：B
解析：
待插入句中的 these heaps of rubbish由指示代词these引导，说明前文提到过heaps of rubbish，只有b选项前面的sand,pebbles,or dunes,sometimes containing seashells or piles of debris能与之对应。
14.Changes in climate have altered Earth's coastlines and their environments.
Changing coastlines affect the total amount of land available for people to live on.
A.The existence of Beringia,a vast landmass that may have supported human life,is still debated by archaeologists.
B.Raised beaches,which may contain indicators of human activity,are often the result of isotactic uplifts and tectonic movements.
C.The expansion and contraction of glaciers caused rises and falls in sea levels all over the world and in some areas,led to radical changes in their flora and fauna.
D.The climate changes that led to alternations in the coastlines of San E.Francisco,Scandinavia,Scotland,Alaska,and Newfoundland isolated species that had once flourished together.
F.Because raised beaches along the Mediterranean Sea were caused by tectonic movements,they contain abundant evidence of ancient civilizations.
答案：ACD
解析：
a选项对应第2段段落大意，正确;b选项的Beringia只是第2段的一个例子，故细节不选;c选项对应第3段主旨，正确;d选项对应第2段的第2，第3和第4句，正确;e选项提到多个具体的地点，为细节，不选;f选项的因果关系在原文中没有体现，排除。