[ 阅读 ] 推理题

Posted 2022-11-23 we1less

Stream Deposit TPO52-1
Paragraph1
A large, swift stream or river can carry all sizes of particles, from clay to boulders. When the current slows down, its competence (how much it can carry) decreases and the stream deposits the largest particles in the streambed. If current velocity continues to decrease - as a flood wanes, for example - B. finer particles settle out on top of the large ones. Thus, a stream sorts its sediment according to size. A waning flood might deposit a layer of gravel, overlain by sand and finally topped by silt and clay. Streams also sort sediment in the downstream direction. A. Many mountain streams are choked with boulders and cobbles, but far downstream, their deltas are composed mainly of fine silt and clay. This downstream sorting is curious because stream velocity generally increases in the downstream direction. Competence increases with velocity, so a river should be able to transport larger particles than its tributaries⽀流 carry. One explanation for downstream sorting is that abrasion wears away the boulders and cobbles to sand and silt as the sediment moves downstream over the years. Thus, only the fine sediment reaches the lower parts of most rivers.

3. According to paragraph 1, all of the following are true of stream sorting EXCEPT
A. Most of the particles in mountain streams pile up behind boulders and cobbles.
B. When particles of different sizes settle in a place, the smaller ones sit atop the larger ones.
C. There are generally more large particles upstream than downstream in a river.
D. In some situations, downstream particles are created from rocks that eroded as they traveled downstream.

S： EXCEPT 排除题 stream sorting

D： A. 

       B. 

       C. 

       D. 

SG：A

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  -------------------------------------------- [ 推理题 ] --------------------------------------------

[ 题型识别 ] infer        imply        suggest        support        conclude  

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[ 推理题答题方法 ]        S  D  SG

S 审题： 判断题型，找出该题主要问的内容

D 定位： 去原文中找题干的定位句，并将该句中通用部分删减掉

        不与文章 [ 标题 | 题干 | 其他选项 ] 重复 / 相似

        记忆每个选项最核心的定位词用于在原文找定位句

SG 顺序改写： 按照原文句子顺序，分别定位(完整)选项， 选择错误的一项

错误选项特征：原文没有(无)、与原文相反(反)、不符合题意(偏题，指的是与题干答非所问)

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[ 推理题分类 ]

直接对比推理

① unlike a, b ...

        b部分出现代词，指代的是句子前面的部分

        a = not b

② compare, whereas, while, in contrast, however ...

隐含对比推理

时间对比推理

① 原文：after, since, later, now, recently, currently...

② 题干：before, prior to , past, last, of his time

应用：时间对比，相应的事件对比，答案加not

推理题规律：答案句通常为 观点句、解释句、过渡句

TPO-19 Discovering the Ice Ages
Paragraph 2: The areas covered by this material were so vast that the ice that deposited it must have been a continental glacier larger than Greenland or Antarctica. Eventually, Agassiz and others convinced geologists and the general public that a great continental glaciation had extended the polar ice caps far into regions that now enjoy temperate climates. For the first time, people began to talk about ice ages. It was also apparent that the glaciation occurred in the relatively recent past because the drift was soft, like freshly deposited sediment. We now know the age of the glaciation accurately from radiometric dating of the carbon-14 in logs buried in the drift. The drift of the last glaciation was deposited during one of the most recent epochs of geologic time, the Pleistocene, which lasted from 1.8 million to 10,000 years ago. Along the east coast of the United States, the southernmost advance of this ice is recorded by the enormous sand and drift deposits of the terminal moraines that form Long Island and Cape Cod.

2. It can be inferred from paragraph 2 that Agassiz and other geologists of his time were not able to determine 
A. which geographic regions had been covered with ice sheets in the last ice age
B. the exact dates at which drifts had been deposited during the last ice age
C. the exact composition of the drifts laid during the last ice age
D. how far south along the east coast of the United States the ice had advanced during the last ice age

S： inferred 推理题 not able to determine

D： of his time 时间对比，找相反时间 - now

S： We now know the age of ...

G：= the exact dates B

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Water in the Desert
Paragraph 1: Rainfall is not completely absent in desert areas, but it is highly variable. An annual rainfall of four inches is often used to define the limits of a desert. The impact of rainfall upon the surface water and groundwater resources of the desert is greatly influenced by landforms. Flats and depressions where water can collect are common features, but they make up only a small part of the landscape.

Which of the following statements about annual rainfall can be inferred from paragraph 1?
A. Flat desert areas receive more annual rainfall than desert areas with mountains.
B. Areas that receive more than four inches of rain per year are not considered deserts.
C. Many areas receive less than four inches of annual rainfall, but only a few are deserts.
D. Annual rainfall has no impact on the groundwater resources of desert areas.

S： inferred 推理题

D： 

S： An annual rainfall of four inches is often used to define the limits of a desert

G： B

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Paragraph 5: Isotopic analysis of shells allowed geologists to measure another glacial effect. They could trace the growth and shrinkage of continental glaciers, even in parts of the ocean where there may have been no great change in temperature—around the equator, for example. The oxygen isotope ratio of the ocean changes as a great deal of water is withdrawn from it by evaporation and is precipitated as snow to form glacial ice. During glaciations, the lighter oxygen-16 has a greater tendency to evaporate from the ocean surface than the heavier oxygen-18 does. Thus, more of the heavy isotope is left behind in the ocean and absorbed by marine organisms. From this analysis of marine sediments, geologists have learned that there were many shorter, more regular cycles of glaciation and deglaciation than geologists had recognized from the glacial drift of the continents alone.
 

3. It can be inferred from paragraph 5 that foraminifera fossil shells containing calcite with high percentages of oxygen-16 were deposited at times when 
A. polar ice extended as far as equatorial regions of land and sea
B. extensive glaciation was not occurring
C. there were no great increases in ocean temperature
D. there was heavy snowfall on continental glaciers

S： inferred 推理题 oxygen-16 deposited

D： 

S： During glaciations, the lighter oxygen-16 has a greater tendency to evaporate from the ocean surface than the heavier oxygen-18 does

G： B

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