阅读题题目及答案第1篇Accordingtoparagraph1,whichofthefollowingistrueoftheLateCretaceousclimate?○Summerswerever下面是小编为大家整理的阅读题题目及答案7篇,供大家参考。
阅读题题目及答案 第1篇
According to paragraph 1, which of the following is true of the Late Cretaceous climate?
○Summers were very warm and winters were very
○Shallow seas on the continents caused frequent temperature
○The climate was very similar to today"s
○The climate did not change dramatically from season to
Paragraph 2: At the end of the Cretaceous, the geological record shows that these seaways retreated from the continents back into the major ocean No one knows 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 Perhaps dinosaurs could not tolerate these extreme temperature changes and became
Which of the following reasons is suggested in paragraph 2 for the extinction of the dinosaurs?
○Changes in the lengths of the days and nights during the late Cretaceous period
○Droughts caused by the movement of seaways back into the oceans
○The change from mild to severe climates during the Late Cretaceous period
○An extreme decrease in the average yearly temperature over 10,ooo years
Paragraph 3: If true, though, why did cold-blooded animals such as snakes, lizards, turtles, and crocodiles survive the freezing winters and torrid summers? These animals are at the mercy of the climate to maintain a livable body It"s hard to understand why they would not be affected, whereas dinosaurs were left too crippled to cope, especially if, as some scientists believe, dinosaurs were Critics also point out that the shallow seaways had retreated from and advanced 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 initially appealing, the hypothesis of a simple climatic change related to sea levels is insufficient to explain all the
Why does the author mention the survival of "snakes, lizards, turtles, and crocodiles" in paragraph 3?
○To argue that dinosaurs may have become extinct because they were not cold-blooded animals
○To question the adequacy of the hypothesis that climatic change related to sea levels caused the extinction of the dinosaurs
○To present examples of animals that could maintain a livable body temperature more easily than dinosaurs
○To support a hypothesis that these animals were not as sensitive to climate changes in the Cretaceous period as they are today
The word "cope" in the passage is closest in meaning to
○ adapt
○ move
○ continue
○ compete
According to paragraph 3, which of the following is true of changes in climate before the Cretaceous period and the effect of these changes on dinosaurs?
○Climate changes associated with the movement of seaways before the Cretaceous period did not cause dinosaurs to become
○Changes in climate before the Cretaceous period caused severe fluctuations in sea level, resulting in the extinction of the
○Frequent changes in climate before the Cretaceous period made dinosaurs better able to maintain a livable body
○Before the Cretaceous period there were few changes in climate, and dinosaurs
word "fluctuations" in the passage is closest in meaning to
○ extremes
○ retreats
○ periods
○ variations
Paragraph 4: Dissatisfaction with conventional explanations for dinosaur extinctions led to a surprising observation that, in turn, has suggested a new Many plants and animals disappear abruptly from the fossil record as one moves from layers of rock documenting the end of the Cretaceous up into rocks representing the beginning 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 Scientists felt that they could get an idea of how long the extinctions took by determining 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 determining the amount of the element iridium (lr) it
Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? In correct choices change the meaning in important ways or leave out essential
○The fossil record suggests that there was an abrupt extinction of many plants and animals at the end of the Mesozoic
○Few fossils of the Mesozoic era have survived in the rocks that mark the end of the
○Fossils from the Cretaceous period of the Mesozoic up to the beginning of the Cenozoic era have been removed from the layers of rock that surrounded
○Plants and animals from the Mesozoic era were unable to survive in the Cenozoic
Paragraph 4: Dissatisfaction with conventional explanations for dinosaur extinctions led to a surprising observation that, in turn, has suggested a new Many plants and animals disappear abruptly from the fossil record as one moves from layers of rock documenting the end of the Cretaceous up into rocks representing the beginning 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 Scientists felt that they could get an idea of how long the extinctions took by determining 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 determining the amount of the element iridium (Ir) it
In paragraph 4, all the following questions are answered EXCEPT:
○Why is there a layer of clay between the rocks of the Cretaceous and Cenozoic?
○Why were scientists interested in determining how long it took to deposit the layer of clay at the end of the Cretaceous?
○What was the effect of the surprising observation scientists made?
○Why did scientists want more information about the dinosaur extinctions at the end of the Cretaceous?
Paragraph 5: Ir has not been common at Earth"s since the very beginning of the planet"s Because it usually exists in a metallic state, it was preferentially incorporated in Earth"s core as the planet cooled and Ir is found in high concentrations in some meteorites, in which the solar system"s original chemical composition is Even today, microscopic meteorites continually bombard Earth, falling on both land and 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 observed amount of Ir in the boundary These calculations suggest that a period of about one million years would have been However, other reliable evidence suggests that the deposition of the boundary clay could not have taken one million So the unusually high concentration of Ir seems to require a special
The word "bombard" in the passage is closest in meaning to
○ approach
○ strike
○ pass
○ circle
Paragraph 5 implies that a special explanation of Ir in the boundary clay is needed because
○the Ir in microscopic meteorites reaching Earth during the Cretaceous period would have been incorporated into Earth"s core
○the Ir in the boundary clay was deposited much more than a million years ago
○the concentration of Ir in the boundary clay is higher than in microscopic meteorites
○the amount of Ir in the boundary clay is too great to have come from microscopic meteorites during the time the boundary clay was deposited
Paragraph 6: In view of these facts, scientists hypothesized that a single large asteroid, about 10 to 15 kilometers across, collided with Earth, and the resulting fallout created the boundary Their calculations show that the impact kicked up a dust cloud that cut off sunlight for several months, inhibiting photosynthesis in plants; decreased surface temperatures on continents to below freezing; caused extreme episodes of acid rain; and significantly raised long-term global temperatures through the greenhouse This disruption of food chain and climate would have eradicated the dinosaurs and other organisms in less than fifty
The word "disruption" in the passage is closest in meaning to
○ exhaustion
○ disturbance
○ modification
○ disappearance
Paragraph 6 mentions all of the following effects of the hypothesized asteroid collision EXCEPT
○ a large dust cloud that blocked sunlight
○ an immediate drop in the surface temperatures of the continents
○ an extreme decrease in rainfall on the continents
○ a long-term increase in global temperatures
Paragraph 5: Ir has not been common at Earth"s since the very beginning of the planet"s Because it usually exists in a metallic state, it was preferentially incorporated in Earth"s core as the planet cooled and Ir is found in high concentrations in some meteorites, in which the solar system"s original chemical composition is Even today, microscopic meteorites continually bombard Earth, falling on both land and 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 observed amount of Ir in the boundary ■ These calculations suggest that a period of about one million years would have been ■However, other reliable evidence suggests that the deposition of the boundary clay could not have taken one million ■So the unusually high concentration of Ir seems to require a special ■
Look at the four squares [■] that indicate where the following sentence could be added to the
Consequently, the idea that the Ir in the boundary clay came from microscopic meteorites cannot be
Where would the sentence best fit?
Directions: An introductory sentence for a brief summary of the passage is provided Complete the summary by selecting the THREE answer choices that express the most important ideas in the Some sentences do not belong in the summary because they express that are not presented in the passage or are minor ideas in the This question is worth 2
For a long time scientists have argued that the extinction of the dinosaurs was related to climate
●
●
●
Answer choices
○A simple climate change does not explain some important data related to the extinction of the dinosaurs at the end of the
○The retreat of the seaways at the end of the Cretaceous has not been fully
○The abruptness of extinctions at the end of the Cretaceous and the high concentration of Ir found in clay deposited at that time have fueled the development of a new
○Extreme changes in daily and seasonal climates preceded the retreat of the seas back into the major ocean
○Some scientists hypothesize that the extinction of the dinosaurs resulted from the effects of an asteroid collision with
○Boundary clay layers like the one between the Mesozoic and Cenozoic are used by scientists to determine the rate at which an extinct species declined
阅读题题目及答案 第2篇
Extinction of the Dinosaurs
Paleozoic Era 334 to 248 million years ago
Mesozoic Era 245 to 65 million years ago
-Triassic Period
-Jurassic Period
-Cretaceous Period
Cenozoic Era 65 million years ago to the present
Paleontologists have argued for a long time that the demise of the dinosaurs was caused by climatic alterations associated with slow changes in the positions of continents and seas resulting from plate Off and on throughout the Cretaceous (the last period of the Mesozoic era, during which dinosaurs flourished), large shallow seas covered extensive areas of the Data from diverse sources, including geochemical evidence preserved in seafloor sediments, indicate that the Late Cretaceous climate was milder than today" The days were not too hot, nor the nights too The summers were not too warm, nor the winters too The shallow seas on the continents probably buffered the temperature of the nearby air, keeping it relatively
At the end of the Cretaceous, the geological record shows that these seaways retreated from the continents back into the major ocean No one knows 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 Perhaps dinosaurs could not tolerate these extreme temperature changes and became
If true, though, why did cold-blooded animals such as snakes, lizards, turtles, and crocodiles survive the freezing winters and torrid summers? These animals are at the mercy of the climate to maintain a livable body It"s hard to understand why they would not be affected, whereas dinosaurs were left too crippled to cope, especially if, as some scientists believe, dinosaurs were Critics also point out that the shallow seaways had retreated from and advanced 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 initially appealing, the hypothesis of a simple climatic change related to sea levels is insufficient to explain all the
Dissatisfaction with conventional explanations for dinosaur extinctions led to a surprising observation that, in turn, has suggested a new Many plants and animals disappear abruptly from the fossil record as one moves from layers of rock documenting the end of the Cretaceous up into rocks representing the beginning 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 Scientists felt that they could get an idea of how long the extinctions took by determining 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 determining the amount of the element iridium (Ir) it
Ir has not been common at Earth"s since the very beginning of the planet"s Because it usually exists in a metallic state, it was preferentially incorporated in Earth"s core as the planet cooled and Ir is found in high concentrations in some meteorites, in which the solar system"s original chemical composition is Even today, microscopic meteorites continually bombard Earth, falling on both land and 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 observed amount of Ir in the boundary These calculations suggest that a period of about one million years would have been However, other reliable evidence suggests that the deposition of the boundary clay could not have taken one million So the unusually high concentration of Ir seems to require a special
In view of these facts, scientists hypothesized that a single large asteroid, about 10 to 15 kilometers across, collided with Earth, and the resulting fallout created the boundary Their calculations show that the impact kicked up a dust cloud that cut off sunlight for several months, inhibiting photosynthesis in plants; decreased surface temperatures on continents to below freezing; caused extreme episodes of acid rain; and significantly raised long-term global temperatures through the greenhouse This disruption of food chain and climate would have eradicated the dinosaurs and other organisms in less than fifty
Paragraph 1: Paleontologists have argued for a long time that the demise of the dinosaurs was caused by climatic alterations associated with slow changes in the positions of continents and seas resulting from plate Off and on throughout the Cretaceous (the last period of the Mesozoic era, during which dinosaurs flourished), large shallow seas covered extensive areas of the Data from diverse sources, including geochemical evidence preserved in seafloor sediments, indicate that the Late Cretaceous climate was milder than today" The days were not too hot, nor the nights too The summers were not too warm, nor the winters too The shallow seas on the continents probably buffered the temperature of the nearby air, keeping it relatively
阅读题题目及答案 第3篇
Paragraph 3：Oil pools are valuable underground accumulations of oil, and oil fields are regions underlain by one or more oil When an oil pool or field has been discovered, wells are drilled into the Permanent towers, called derricks, used to be built to handle the long sections of drilling Now portable drilling machines are set up and are then dismantled and When the well reaches a pool, oil usually rises up the well because of its density difference with water beneath it or because of the pressure of expanding gas trapped above Although this rise of oil is almost always carefully controlled today, spouts of oil, or gushers, were common in the Gas pressure gradually dies out, and oil is pumped from the Water or steam may be pumped down adjacent wells to help push the oil At a refinery, the crude oil from underground is separated into natural gas, gasoline, kerosene, and various Petrochemicals such as dyes, fertilizer, and plastic are also manufactured from the
Which of the following can be inferred from paragraph 3 about gushers?
They make bringing the oil to the surface
They signal the presence of huge oil
They waste more oil than they
They are unlikely to occur
托福阅读推断题练习题答案：4
阅读题题目及答案 第4篇
Paragraph 1: Groundwater is the word used to describe water that saturates the ground, filling all the available By far the most abundant type of groundwater is meteoric water; this is the groundwater that circulates as part of the water Ordinary meteoric water is water that has soaked into the ground from the surface, from precipitation (rain and snow) and from lakes and There it remains, sometimes for long periods, before emerging at the surface At first thought it seems incredible that there can be enough space in the “solid” ground underfoot to hold all this
Which of the following can be inferred from paragraph 1 about the ground that we walk on?
It cannot hold rainwater for long periods of
It prevents most groundwater from
It has the capacity to store large amounts of
It absorbs most of the water it contains from
托福阅读推断题练习题答案：3
阅读题题目及答案 第5篇
奥加拉拉蓄水层的枯竭
19世纪80年代，在美国中部北美大平原的广阔草原上定居着农场主们和牧场主们。这里有着半干旱的气候，在人们定居50年后，它支撑了一个以畜牧业和小麦种植为主的低密度农业经济。然而，在20世纪初，人们发现北美大平原的大部地下是巨大的蓄水层(含有大量地下水的岩层)。这个蓄水层因曾经在这里定居过的奥加拉拉苏族印第安人而得名，被称作奥加拉拉蓄水层。
奥加拉拉蓄水层属于砂岩结构，在从德克萨斯州西北到南达科塔州南部的地下绵延了万平方公里。雨水和融雪自3万年前便开始在奥加拉拉蓄积。据估计，奥加拉拉蓄水层的含水量足以填满休伦湖，但不幸的是，在目前该地区半干旱的气候条件下，奥加拉拉蓄水层的蓄水能力极低，每年仅半厘米左右。
20世纪30年代初，奥加拉拉正处于干旱时期，人们打出了第一口井。灌溉农业的迅速扩张，特别是20世纪50年代之后，改变了这一地区的经济。目前人们已经在奥加拉拉地区共开凿了10万多口井。日喷水量达到450万升的现代灌溉设备，形成了一个圆形绿岛作物为主的景观。奥加拉拉蓄水层支撑了北美大平原地区棉花、高粱、小麦、玉米的灌溉需求。此外，美国40%谷饲养的肉牛在这里被育肥。
考虑到几乎没有补充率(实质上没有自然水资源进行补充)，这种有限地下水资源前所未有的发展已经引起了该地区地下水位的急剧下降。在20世纪30年代，井下15米就有丰富的水资源，而现在，必须挖掘到45米到60米甚至更深的地方才行。有的地方地下水位的下降速度甚至达到了每年1米，迫使人们周期性的加深水井并使用更有力的水泵。按现今的下降速度来估计，大部分地下蓄水将在40年内耗尽。这种现象在气候最干旱的德克萨斯州尤为严重。大量的水被从地下抽起，蓄水层含水量最少。据估计，到20XX年，德克萨斯州余下的奥加拉拉含水只能支持1980年灌溉面积的35%到40%。
农场主们对无法避免的奥加拉拉蓄水层枯竭的反应各不相同。很多人已经开始尝试通过降低灌溉频率或者改种需水较少的庄稼来节约水资源。而另外一些人却抱着趁水资源还能产生经济效益就应抓紧利用的想法，继续种植高价值的棉花等农作物。当那些想节水的农场主得知邻居们通过大量耗水的种植而盈利的时候，他们的热情降低了，从而导致了整个区域的供水量的减少。
在即将到来的水资源供应危机面前，人们提出了一些宏伟的供水计划，比如将密西西比河、密苏里河或者阿肯色河的水通过运河或管道运到需要用水的地方。不幸的是，通过以上任何一种方式获得水资源都会将抽水的成本提高10倍以上，进而导致这一地区的灌溉农产品成本在国内和国际市场上失去竞争力。最近一些有希望获得成功的试验试图通过向土壤中注入压力，释放水层上方土壤中的毛细管水。即使这样行之有效，抽水成本会变到原来的3倍。基因工程也会通过继续研发抗旱作物新品种，帮助解决部分难题。无论这次水资源危机的最终结果如何，显然，北美大平原地区灌溉水资源再也不会像20世纪中期农业繁荣时期的那样充足并且廉价了。
阅读题题目及答案 第6篇
to paragraph 1, which of the following statements about the High Plains is true?
○Until farmers and ranchers settled there in the 1880s, the High Plains had never been
○The climate of the High Plains is characterized by higher-than-average
○The large aquifer that lies underneath the High Plains was discovered by the Ogallala Sioux
○Before the early 1900s there was only a small amount of farming and ranching in the High
Paragraph 2: The Ogallala aquifer is a sandstone formation that underlies some 583,000 square kilometers of land extending from northwestern Texas to southern South Water from rains and melting snows has been accumulating in the Ogallala for the past 30,000 Estimates indicate that the aquifer contains enough water to fill Lake Huron, but unfortunately, under the semiarid climatic conditions that presently exist in the region, rates of addition to the aquifer are minimal, amounting to about half a centimeter a
According to paragraph 2, all of the following statements about the Ogallala aquifer are true EXCEPT:
○The aquifer stretches from South Dakota to
○The aquifer"s water comes from underground
○Water has been gathering in the aquifer for 30,000
○The aquifer"s water is stored in a layer of
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
○Despite the current impressive size of the Ogallala aquifer, the region"s climate keeps the rates of water addition very
○Although the aquifer has been adding water at the rate of only half a centimeter a year, it will eventually accumulate enough water of fill Lake
○Because of the region"s present climatic conditions, water is being added each year to the
○Even when the region experiences unfortunate climatic conditions, the rates of addition of water continue to
Paragraph 3: The first wells were drilled into the Ogallala during the drought years of the early The ensuing rapid expansion of irrigation agriculture, especially from the 1950s onward, transformed the economy of the More than 100,000 wells now tap the Modern irrigation devices, each capable of spraying million liters of water a day, have produced a landscape dominated by geometric patterns of circular green islands of Ogallala water has enabled the High Plains region to supply significant amounts of the cotton, sorghum, wheat, and corn grown in the United In addition, 40 percent of American grain-fed beef cattle are fattened
The word "ensuing" in the passage is closest in meaning to
○continuing
○surprising
○initial
○subsequent
In paragraph 3, why does the author provide the information that 40 percent of American cattle are fattened in the High Plains?
○To suggest that crop cultivation is not the most important part of the economy of the High Plains
○To indicate that not all economic activity in the High Plains is dependent on irrigation
○To provide another example of how water from the Ogallala has transformed the economy of the High Plains
○To contrast cattle-fattening practices in the High Plains with those used in other region of the United States
Paragraph 4: This unprecedented development of a finite groundwater resource with an almost negligible natural recharge rate-that is, virtually no natural water source to replenish the water supply-has caused water tables in the region to fall In the 1930s, wells encountered plentiful water at a depth of about 15 meters; currently, they must be dug to depths of 45 to 60 meters or In places, the water table is declining at a rate of a meter a year, necessitating the periodic deepening of wells and the use of ever-more-powerful It is estimated that at current withdrawal rates, much of the aquifer will run dry within 40 The situation is most critical in Texas, where the climate is driest, the greatest amount of water is being pumped, and the aquifer contains the least It is projected that the remaining Ogallala water will, by the year 20XX, support only 35 to 40 percent of the irrigated acreage in Texas that is supported in
The word "unprecedented" in the passage is closest in meaning to
○difficult to control
○without any restriction
○unlike anything in the past
○rapidly expanding
The word "virtually" in the passage is closest in meaning to
○clearly
○perhaps
○frequently
○almost
According to paragraph 4, all of following are consequences of the heavy use of the Ogallala aquifer for irrigation EXCEPT:
○The recharge rate of the aquifer is
○Water tables in the region are becoming increasingly
○Wells now have to be dug to much greater depths than
○Increasingly powerful pumps are needed to draw water from the
According to paragraph 4, compared with all other states that use Ogallala water for irrigation, Texas
○has the greatest amount of farmland being irrigated with Ogallala water
○contains the largest amount of Ogallala water underneath the soil
○is expected to face the worst water supply crisis as the Ogallala runs dry
○uses the least amount of Ogallala water for its irrigation needs
Paragraph 5: The reaction of farmers to the inevitable depletion of the Ogallala Many have been attempting to conserve water by irrigating less frequently or by switching to crops that require less Others, however, have adopted the philosophy that it is best to use the water while it is still economically profitable to do so and to concentrate on high-value crops such as The incentive of the farmers who wish to conserve water is reduced by their knowledge that many of their neighbors are profiting by using great amounts of water, and in the process are drawing down the entire region"s water
The word "inevitable" in the passage is closest in meaning to
○unfortunate
○predictable
○unavoidable
○final
Paragraph 5 mentions which of the following as a source of difficulty for some farmers who try to conserve water?
○Crops that do not need much water are difficult to grow in the High
○Farmers who grow crops that need a lot of water make higher
○Irrigating less frequently often leads to crop
○Few farmers are convinced that the aquifer will eventually run
Paragraph 6: In the face of the upcoming water supply crisis, a number of grandiose schemes have been developed to transport vast quantities of water by canal or pipeline from the Mississippi, the Missouri, or the Arkansas Unfortunately, the cost of water obtained through any of these schemes would increase pumping costs at least tenfold, making the cost of irrigated agricultural products from the region uncompetitive on the national and international Somewhat more promising have been recent experiments for releasing capillary water (water in the soil) above the water table by injecting compressed air into the Even if this process proves successful, however, it would almost triple water Genetic engineering also may provide a partial solution, as new strains of drought-resistant crops continue to be Whatever the final answer to the water crisis may be, it is evident that within the High Plains, irrigation water will never again be the abundant, inexpensive resource it was during the agricultural boom years of the mid-twentieth
to paragraph 6, what is the main disadvantage of the proposed plans to transport river water to the High Plains?
○The rivers cannot supply sufficient water for the farmer"s
○Increased irrigation costs would make the products too
○The costs of using capillary water for irrigation will
○Farmers will be forced to switch to genetically engineered
Paragraph 5: The reaction of farmers to the inevitable depletion of the Ogallala Many have been attempting to conserve water by irrigating less frequently or by switching to crops that require less █Others, however, have adopted the philosophy that it is best to use the water while it is still economically profitable to do so and to concentrate on high-value crops such as █The incentive of the farmers who wish to conserve water is reduced by their knowledge that many of their neighbors are profiting by using great amounts of water, and in the process are drawing down the entire region"s water █
Paragraph 6: In the face of the upcoming water supply crisis, a number of grandiose schemes have been developed to transport vast quantities of water by canal or pipeline from the Mississippi, the Missouri, or the Arkansas █Unfortunately, the cost of water obtained through any of these schemes would increase pumping costs at least tenfold, making the cost of irrigated agricultural products from the region uncompetitive on the national and international Somewhat more promising have been recent experiments for releasing capillary water (water in the soil) above the water table by injecting compressed air into the Even if this process proves successful, however, it would almost triple water Genetic engineering also may provide a partial solution, as new strains of drought-resistant crops continue to be Whatever the final answer to the water crisis may be, it is evident that within the High Plains, irrigation water will never again be the abundant, inexpensive resource it was during the agricultural boom years of the mid-twentieth
at the four squares [█] that indicate where the following sentence could be added to the passage
But even if uncooperative farmers were to join in the conservation efforts, this would only delay the depletion of the
Where would the sentence best fit? Click on a square to add the sentence to the
An introductory sentence for a brief summary of the passage is provided Complete the summary by selecting the THREE answer choices that express the most important ideas in the Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the This question is worth 2
The Ogallala aquifer is a large underground source of water in the High Plains region of the United
●
●
●
Answer choices
○The use of the Ogallala for irrigation has allowed the High Plains to become one of the most productive agricultural regions in the United
○Given the aquifer"s low recharge rate, its use for irrigation is causing water tables to drop and will eventually lead to its
○Releasing capillary water and introducing drought-resistant crops are less-promising solutions to the water supply crisis than bringing in river water
○The periodic deepening of wells and the use of more-powerful pumps would help increase the natural recharge rate of the
○In Texas, a great deal of attention is being paid to genetic engineering because it is there that the most critical situation
○Several solutions to the upcoming water supply crisis have been proposed, but none of them promises to keep the costs of irrigation
阅读题题目及答案 第7篇
参考翻译：恐龙的灭绝
很长时间以来，古生物学家们认为恐龙的灭亡是与因地质构造而引起的海洋和大陆位置变迁相关的气候变化所致。在整个白垩纪(中生代的最后的一段时间，这时恐龙正值繁盛)，广阔的浅海覆盖了大量的陆地。各方面的数据，包括海床沉积中的地理化学证据，都表明白垩纪后期的气候比现在的气候要温和得多。白天不是很热，夜间也不是很寒冷。夏天不是太炎热，而冬天也不是太寒冷。大陆上的浅海可能使其附近的空气少受影响，以保持相对稳定的温度。
在白垩纪后期，地质资料表明这些浅海都从大陆退回到主要的海洋盆地内了，没有人明白为什么。大约在100 000年内，海洋收缩了，世界的气候也随之变得更极端：白天更热，夜间更冷，夏天更炎热，冬天更寒冷。恐龙或许就是因为无法忍受这种严峻的气温变化因而灭绝。
如果真是这样，那么为什么冷血动物，比如蛇类、蜥蜴、乌龟和鳄鱼却能够幸免于寒冬和酷夏呢?这些动物都是依赖于气温以使其身体保持适合生存的温度。很难理解它们为什么毫不受影响，然而恐龙却如此的无能以至于无法适应，尤其是有些科学家认为恐龙是热血动物。批评者们也指出浅海在中生代曾有过无数次的进入大陆而又退回盆地的过程，所以为什么恐龙在前面的海洋起伏中能幸免于难，而在这一次中却不能呢?尽管最初人们这样认为，但是简单的与海平面高度有关的气候变化假设是不足以解释所有数据的。
对传统的关于恐龙灭绝解释的不满使得人们反过来惊奇的发现，从而产生了新的假设。当人们对比白垩纪后期的岩层资料和新生代(中生代后面的一个时期)早期的资料时发现很多植物和动物都突然地消失了。在白垩纪最后的一层岩石和新生代的第一层岩石之间，常有一层很薄的粘土。科学家们感觉到他们可以通过确定这层一厘米厚的粘土层中元素铱的含量来推测其的沉积时间，进而推测大灭绝所用的时间。
自从地球以来，铱元素在地球的表面上就不常见。因为它通常是以金属状态存在，并随着地球的冷却和固结而优先地合并到地核中了。在一些陨石中，依可能会高度富集，而这里常保存着太阳系内原始的化学组成。直到今天，小型的陨石也在连续不断地撞击地球，并掉落在陆地和海洋中。通过确定在一段给定时间内掉落在地球上的这种陨石的数量，科学家们就可以确定沉积隔层粘土的形成时间。这种计算表明形成这种沉积可能需要一百万年。然而其他可靠的证据则表明沉积这层粘土不可能花费了一百万年。所以这种不正常的铱的富集可能需要一种特殊的解释。
考虑到这些事实，科学家们就假设有一个较大的小行星，直径差不多有10到15公里，曾与地球相撞，所以碰撞扬起的灰尘等就形成了这层粘土层。他们的计算表明撞击扬起的灰尘遮挡了阳光达几个月之久，阻止了植物的光合作用，将陆地上的气温降到了零点之下，导致酸雨，通过温室效应造成了长期的、严重的全球升温。这种对食物链和气候的极大扰乱将可使恐龙和其他生物在不到50年的时间内绝迹。
推荐访问:题目 答案 阅读 阅读题题目及答案7篇 阅读题题目及答案(集合7篇) 阅读题的题目及答案