文本阅读题及答案第1篇参考翻译：火星上的流水来自照片的证据显示在火星的表面曾有过大量的液态水。两种流动形式已经被发现：径流通道和外流通道。径流通道发现于南部的高地。这些流动形式有着庞大的系统--有时竟下面是小编为大家整理的文本阅读题及答案集锦10篇,供大家参考。
文本阅读题及答案 第1篇
参考翻译：火星上的流水
来自照片的证据显示在火星的表面曾有过大量的液态水。两种流动形式已经被发现：径流通道和外流通道。径流通道发现于南部的高地。这些流动形式有着庞大的系统--有时竟有数百千米长--这些通道相互交错、扭转，并可能汇入更大更宽的通道中。它们和地球上的河流系统非常相似，地质学家们认为它们是以前曾将火星上的雨水从高山携带到峡谷中的那些河流干涸后的遗迹。火星上的径流通道存在于40亿年以前(就是火星高地的年龄)，那时候火星的大气层更厚，地表更暖和，并且液态水分布很广。
外流通道可能是很久以前火星上洪灾的遗迹。它们只形成于赤道附近，并一般没有形成广泛的交错的网络。相反，它们可能是携带大量水从南部高地到北部平原的排水系统。由泛滥的洪水而产生的激流可能也形成奇怪的泪滴状小岛(就像是在低潮时湿沙地或海滩上看到的缩小版本一样)，已经在靠近出流通道末尾处的平原上被看到。从这些通道的宽度和深度可判断，当时流速一定很大--有可能是亚马逊河的每秒钟105吨的流量的一百多倍。大约在30亿年以前，北部火山平原形成的同时，洪水改变了外流通道的形状。
一些科学家认为早期的火星上广泛存在着河流，湖泊甚至是海洋。一份20XX年的对火星全球的调查照片显示了一个科学家们认为是三角洲的构造--一个扇形的沉积物和水流通道的网络，河流可能是从这里流入了一个更大的水体;在这种情况下，它可能是南部高地的一个火山口湖泊。其他研究者做了更大胆的猜测，他们认为那些数据表明早期在火星表面存在大量的水。一张关于火星北部极地地区的电脑图片说明有可能有一个古老的海洋覆盖了大部分北部的低洼处。那座有大约3 000公里宽，9公里深的希腊盆地也可能是火星海洋。
这些观点仍然有争议。支持者们指出照片里显示的台地"海滩"可以是由湖泊或者海洋蒸发干涸之后或者海退之后形成的。但是反对者认为这些台地也可能是由于地质活动造成的，也许与使得北半球比南半球地势更低的地质力量有关，在这种情况下，它们就和火星水系没有任何关系。而且，20XX发布的火星全球调查数据也表明火星表面含有太少的碳化岩层--含有碳氧化合物的岩层--它们应该是在古代海洋中大量形成的。这些岩层的缺失支持了火星是一个又冷又干燥的星球这一说法，并且不可能拥有形成湖泊和海洋的温和气候。然而，更新的数据表明至少该星球上的一些部分表面的确在过去的很长时间内存在液态水。
除了在20XX年发现了一些小规模的、不确定的溪谷以外，宇航员到目前为止还没有在星球的什么地方找到液态水存在的直接证据。而且火星大气中的水蒸气的含量也是微乎其微的。然而就算不考虑尚未证明的古代海洋存在的观点，出流通道的广泛存在就足以证明在火星上曾有大量的水体，水都去了哪里呢?答案可能是火星上所有的水实际上现在已经封存在其地下的永久冻层中，并且在极地地区最多。
文本阅读题及答案 第2篇
参考翻译：矿物质和植物
研究表明，某些矿物质是植物正常生长发育所必需的。土壤是这些矿物质的来源，它们通过水分被植物从土壤中吸收。即使是元素状态为气体的氮，也通常作为硝酸根离子从土壤中被吸收。众所周知，一些土壤缺乏微量营养素，因此大多数植物不能生长。例如所谓的蛇纹岩土壤，由于缺乏钙，只有那些能忍受如此低含量的钙的植物才能够存活。在现代农业，土壤矿物质枯竭是一个大问题，因为收割庄稼切断了养分返回土壤的循环。
矿物质缺乏通常可由特定的症状检测出来，如褪绿(叶绿素损失导致黄叶或白叶的现象)、坏疽(孤立的坏死斑)、花青素的形成(形成深红色叶片和茎色素沉积)、发育不良以及草本植物长木质组织。土壤最常缺乏的是氮和磷。氮缺乏植物表现出了刚才描述的许多症状：叶片黄化、茎短而细以及发生在茎、叶柄以及下叶表面的花青素变色。磷缺乏的植物往往发育不良，叶片变成特殊的深绿色，经常伴随着花青素的积累。由于磷流向新生的组织，通常较老的叶片首先受到影响。铁缺乏症的特点是嫩叶的叶脉之间萎黄。
大多数关于营养素缺乏症的研究都基于水培法，即在无土营养液中培养。这项技术允许研究人员创造缺乏某种营养素的溶液，然后观察对植物生长造成的影响。水培法的应用已经超越了基础研究，因为它促进了温室蔬菜在冬季的生长。空气培养法，一种把植物悬挂起来，将其根部喷上营养液的技术，是另外一种无土栽培的方法。
虽然缺乏矿物质会抑制植物生长，但某些矿物质过量可能会有毒，同样也会抑制植物生长。含有高浓度的氯化钠和其他盐类的盐碱土壤抑制植物生长，于是研究继续集中开发耐盐农作物品种。着重研究重金属的毒性作用，如铅、镉、汞、铝;然而即使是铜和锌这样的必需元素，如果浓度过高也会产生毒性。虽然大多数植物无法在这种土壤生存，某些植物却能够忍耐如此高含量的矿物质。
科学家早前就了解到，某些所谓的富集植物能够比普通植物多集中100倍甚至更多的矿物质。一项对已知富集植物的调查表明，它们中75%积聚了镍，而钴、铜、锌、锰、铅和镉则是其他选择性聚集的矿物质。富集植物存在于整个世界范围，它们可能是草本植物、灌木或树。芥属、大戟属、豆科和禾本科植物中的许多成员都是靠前的富集植物。许多富集植物被发现于热带和亚热带，金属可以为植物提供保护，对抗植食昆虫和细菌病原体。
直到最近研究者才考虑用这些植物来清理已经被有毒重金属污染的土壤和废弃物物处理点--一种被称为植物修复法的修复方法。这套方案首先从在目标区域种植超积累物种开始，如在废弃矿井和被径流污染的灌溉池塘。有毒矿物质首先被根吸收，随后被运送至茎和叶。收割下来的枝叶将被焚烧以移除有毒化合物或被制成混合肥料回收金属用于工业。经过几年的种植和收割，该污染点将被修复，而其造价远比修复污染土壤的标准做法--挖掘和填埋来得低。举例来说，在实地试验中，高山菥蓂从靠近一个锌冶炼厂的土壤中去除了锌和镉，原产自巴基斯坦和印度的印度芥菜可以将染土壤中硒的水平有效地降低了50%。
文本阅读题及答案 第3篇
Running Water on Mars
Photographic evidence suggests that liquid water once existed in great quantity on the surface of Two types of flow features are seen: runoff channels and outflow Runoff channels are found in the southern These flow features are extensive systems-sometimes hundreds of kilometers in total length-of interconnecting, twisting channels that seem to merge into larger, wider They bear a strong resemblance to river systems on Earth, and geologists think that they are dried-up beds of long-gone rivers that once carried rainfall on Mars from the mountains down into the Runoff channels on Mars speak of a time 4 billion years ago (the age of the Martian highlands), when the atmosphere was thicker, the surface warmer, and liquid water
Outflow channels are probably relics of catastrophic flooding on Mars long They appear only in equatorial regions and generally do not form extensive interconnected Instead, they are probably the paths taken by huge volumes of water draining from the southern highlands into the northern The onrushing water arising from these flash floods likely also formed the odd teardrop-shaped "islands" (resembling the miniature versions seen in the wet sand of our beaches at low tide) that have been found on the plains close to the ends of the outflow Judging from the width and depth of the channels, the flow rates must have been truly enormous-perhaps as much as a hundred times greater than the 105 tons per second carried by the great Amazon Flooding shaped the outflow channels approximately 3 billion years ago, about the same times as the northern volcanic plains
Some scientists speculate that Mars may have enjoyed an extended early Period during which rivers, lakes, and perhaps even oceans adorned its A 20XX Mars Global Surveyor image shows what mission specialists think may be a delta-a fan-shaped network of channels and sediments where a river once flowed into a larger body of water, in this case a lake filling a crater in the southern Other researchers go even further, suggesting that the data provide evidence for large open expenses of water on the early Martian A computer-generated view of the Martian north polar region shows the extent of what may have been an ancient ocean covering much of the northern The Hellas Basin, which measures some 3,000 kilometers across and has a floor that lies nearly 9 kilometers below the basin"s rim, is another candidate for an ancient Martian
These ideas remain Proponents point to features such as the terraced "beaches" shown in one image, which could conceivably have been left behind as a lake or ocean evaporated and the shoreline But detractors maintain that the terraces could also have been created by geological activity, perhaps related to the geologic forces that depressed the Northern Hemisphere far below the level of the south, in which case they have nothing whatever to do with Martian Furthermore, Mars Global Surveyor data released in 20XX seem to indicate that the Martian surface contains too few carbonate rock layers-layers containing compounds of carbon and oxygen-that should have been formed in abundance in an ancient Their absence supports the picture of a cold, dry Mars that never experienced the extended mild period required to form lakes and However, more recent data imply that at least some parts of the planet did in fact experience long periods in the past during which liquid water existed on the
Aside from some small-scale gullies (channels) found since 20XX, which are inconclusive, astronomers have no direct evidence for liquid water anywhere on the surface of Mars today, and the amount of water vapor in the Martian atmosphere is Yet even setting aside the unproven hints of ancient oceans, the extent of the outflow channels suggests that a huge total volume of water existed on Mars in the Where did all the water go? The answer may be that virtually all the water on Mars is now locked in the permafrost layer under the surface, with more contained in the planet"s polar
Paragraph 1: Photographic evidence suggests that liquid water once existed in great quantity on the surface of Two types of flow features are seen: runoff channels and outflow Runoff channels are found in the southern These flow features are extensive systems-sometimes hundreds of kilometers in total length-of interconnecting, twisting channels that seem to merge into larger, wider They bear a strong resemblance to river systems on Earth, and geologists think that they are dried-up beds of long-gone rivers that once carried rainfall on Mars from the mountains down into the Runoff channels on Mars speak of a time 4 billion years ago (the age of the Martian highlands), when the atmosphere was thicker, the surface warmer, and liquid water
文本阅读题及答案 第4篇
Minerals and Plants
Research has shown that certain minerals are required by plants for normal growth and The soil is the source of these minerals, which are absorbed by the plant with the water from the Even nitrogen, which is a gas in its elemental state, is normally absorbed from the soil as nitrate Some soils are notoriously deficient in micro nutrients and are therefore unable to support most plant So-called serpentine soils, for example, are deficient in calcium, and only plants able to tolerate low levels of this mineral can In modern agriculture, mineral depletion of soils is a major concern, since harvesting crops interrupts the recycling of nutrients back to the
Mineral deficiencies can often be detected by specific symptoms such as chlorosis (loss of chlorophyll resulting in yellow or white leaf tissue), necrosis (isolated dead patches), anthocyanin formation (development of deep red pigmentation of leaves or stem), stunted growth, and development of woody tissue in an herbaceous Soils are most commonly deficient in nitrogen and Nitrogen-deficient plants exhibit many of the symptoms just Leaves develop chlorosis; stems are short and slender, and anthocyanin discoloration occurs on stems, petioles, and lower leaf Phosphorus-deficient plants are often stunted, with leaves turning a characteristic dark green, often with the accumulation of Typically, older leaves are affected first as the phosphorus is mobilized to young growing Iron deficiency is characterized by chlorosis between veins in young
Much of the research on nutrient deficiencies is based on growing plants hydroponically, that is, in soilless liquid nutrient This technique allows researchers to create solutions that selectively omit certain nutrients and then observe the resulting effects on the Hydroponics has applications beyond basic research, since it facilitates the growing of greenhouse vegetables during Aeroponics, a technique in which plants are suspended and the roots misted with a nutrient solution, is another method for growing plants without
While mineral deficiencies can limit the growth of plants, an overabundance of certain minerals can be toxic and can also limit Saline soils, which have high concentrations of sodium chloride and other salts, limit plant growth, and research continues to focus on developing salt-tolerant varieties of agricultural Research has focused on the toxic effects of heavy metals such as lead, cadmium, mercury, and aluminum; however, even copper and zinc, which are essential elements, can become toxic in high Although most plants cannot survive in these soils, certain plants have the ability to tolerate high levels of these
Scientists have known for some time that certain plants, called hyperaccumulators, can concentrate minerals at levels a hundredfold or greater than A survey of known hyperaccumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of Hyperaccumulators run the entire range of the plant They may be herbs, shrubs, or Many members of the mustard family, spurge family, legume family, and grass family are top Many are found in tropical and subtropical areas of the world, where accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial
Only recently have investigators considered using these plants to clean up soil and waste sites that have been contaminated by toxic levels of heavy metals-an environmentally friendly approach known as This scenario begins with the planting of hyperaccumulating species in the target area, such as an abandoned mine or an irrigation pond contaminated by Toxic minerals would first be absorbed by roots but later relocated to the stem and A harvest of the shoots would remove the toxic compounds off site to be burned or composted to recover the metal for industrial After several years of cultivation and harvest, the site would be restored at a cost much lower than the price of excavation and reburial, the standard practice for remediation of contaminated For examples, in field trials, the plant alpine pennycress removed zinc and cadmium from soils near a zinc smelter, and Indian mustard, native to Pakistan and India, has been effective in reducing levels of selenium salts by 50 percent in contaminated
Paragraph 1: Research has shown that certain minerals are required by plants for normal growth and The soil is the source of these minerals, which are absorbed by the plant with the water from the Even nitrogen, which is a gas in its elemental state, is normally absorbed from the soil as nitrate Some soils are notoriously deficient in micro nutrients and are therefore unable to support most plant So-called serpentine soils, for example, are deficient in calcium, and only plants able to tolerate low levels of this mineral can In modern agriculture, mineral depletion of soils is a major concern, since harvesting crops interrupts the recycling of nutrients back to the
文本阅读题及答案 第5篇
According to paragraph 1, what is true of plants that can grow in serpentine soil?
○ They absorb micronutrients unusually
○ They require far less calcium than most plants
○ They are able to absorb nitrogen in its elemental
○ They are typically crops raised for
Paragraph 2: Mineral deficiencies can often be detected by specific symptoms such as chlorosis (loss of chlorophyll resulting in yellow or white leaf tissue), necrosis (isolated dead patches), anthocyanin formation (development of deep red pigmentation of leaves or stem), stunted growth, and development of woody tissue in an herbaceous Soils are most commonly deficient in nitrogen and Nitrogen-deficient plants exhibit many of the symptoms just Leaves develop chlorosis; stems are short and slender, and anthocyanin discoloration occurs on stems, petioles, and lower leaf Phosphorus-deficient plants are often stunted, with leaves turning a characteristic dark green, often with the accumulation of Typically, older leaves are affected first as the phosphorus is mobilized to young growing Iron deficiency is characterized by chlorosis between veins in young
The word "exhibit" in the passage is closest in meaning to
○ fight off
○ show
○ cause
○ spread
According to paragraph 2, which of the following symptoms occurs in phosphorus-deficient plants but not in plants deficient in nitrogen or iron?
○ Chlorosis on leaves
○ Change in leaf pigmentation to a dark shade of green
○ Short, stunted appearance of stems
○ Reddish pigmentation on the leaves or stem
According to paragraph 2, a symptom of iron deficiency is the presence in young leaves of
○ deep red discoloration between the veins
○ white or yellow tissue between the veins
○ dead spots between the veins
○ characteristic dark green veins
Paragraph 3: Much of the research on nutrient deficiencies is based on growing plants hydroponically, that is, in soilless liquid nutrient This technique allows researchers to create solutions that selectively omit certain nutrients and then observe the resulting effects on the Hydroponics has applications beyond basic research, since it facilitatesthe growing of greenhouse vegetables during Aeroponics, a technique in which plants aresuspended and the roots misted with a nutrient solution, is another method for growing plants without
The word "facilitates" in the passage is closest in meaning to
○ slows down
○ affects
○ makes easier
○ focuses on
According to paragraph 3, what is the advantage of hydroponics for research on nutrient deficiencies in plants?
○ It allows researchers to control what nutrients a plant
○ It allows researchers to observe the growth of a large number of plants
○ It is possible to directly observe the roots of
○ It is unnecessary to keep misting plants with nutrient
The word "suspended" in the passage is closest in meaning to
○ grown
○ protected
○ spread out
○ hung
Paragraph 5: Scientists have known for some time that certain plants, called hyperaccumulators, can concentrate minerals at levels a hundredfold or greater than A survey of known hyperaccumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of Hyperaccumulators run the entire range of the plant They may be herbs, shrubs, or Many members of the mustard family, spurge family, legume family, and grass family are top Many are found in tropical and subtropical areas of the world, where accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial
Why does the author mention "herbs", "shrubs", and "trees"?
○ To provide examples of plant types that cannot tolerate high levels of harmful
○ To show why so many plants are
○ To help explain why hyperaccumulators can be found in so many different
○ To emphasize that hyperaccumulators occur in a wide range of plant
The word "afford" in the passage is closest in meaning to
○ offer
○ prevent
○ increase
○ remove
Paragraph 6: Only recently have investigators considered using these plants to clean up soil and waste sites that have been contaminated by toxic levels of heavy metals-an environmentally friendly approach known as This scenario begins with the planting of hyperaccumulating species in the target area, such as an abandoned mine or an irrigation pond contaminated by Toxic minerals would first be absorbed by roots but later relocated to the stem and A harvest of the shoots would remove the toxic compounds off site to be burned or composted to recover the metal for industrial After several years of cultivation and harvest, the site would be restored at a cost much lower than the price of excavation and reburial, the standard practice for remediation of contaminated For examples, in field trials, the plant alpine pennycress removed zinc and cadmium from soils near a zinc smelter, and Indian mustard, native to Pakistan and India, has been effective in reducing levels of selenium salts by 50 percent in contaminated
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
○ Before considering phytoremediation, hyperaccumulating species of plants local to the target area must be
○ The investigation begins with an evaluation of toxic sites in the target area to determine the extent of
○ The first step in phytoremediation is the planting of hyperaccumulating plants in the area to be cleaned
○ Mines and irrigation ponds can be kept from becoming contaminated by planting hyperaccumulating species in targeted
It can be inferred from paragraph 6 that compared with standard practices for remediation of contaminated soils, phytoremediation
○ does not allow for the use of the removed minerals for industrial purposes
○ can be faster to implement
○ is equally friendly to the environment
○ is less suitable for soils that need to be used within a short period of time
Why does the author mention "Indian mustard"?
○ To warn about possible risks involved in phytoremediation
○ To help illustrate the potential of phytoremediation
○ To show that hyperaccumulating plants grow in many regions of the world
○ To explain how zinc contamination can be reduced
Paragraph 5: Scientists have known for some time that certain plants, called hyperaccumulators, can concentrate minerals at levels a hundredfold or greater than ■A survey of known hyperaccumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of ■Hyperaccumulators run the entire range of the plant ■They may be herbs, shrubs, or ■Many members of the mustard family, spurge family, legume family, and grass family are top Many are found in tropical and subtropical areas of the world, where accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial
Look at the four squares [■] that indicate where the following sentence could be added to the
Certain minerals are more likely to be accumulated in large quantities than
Where could 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 answer choices 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
Plants need to absorb certain minerals from the soil in adequate quantities for normal growth and
●
●
●
Answer Choices
○Some plants are able to accumulate extremely high levels of certain minerals and thus can be used to clean up soils contaminated with toxic levels of these
○Though beneficial in lower levels, high levels of salts, other minerals, and heavy metals can be harmful to
○When plants do not absorb sufficient amounts of essential minerals, characteristic abnormalities
○Because high concentrations of sodium chloride and other salts limit growth in most plants, much research
has been done in an effort to develop salt-tolerant agricultural
○Some plants can tolerate comparatively low levels of certain minerals, but such plants are of little use for recycling nutrients back into depleted
○Mineral deficiencies in many plants can be cured by misting their roots with a nutrient solution or by transferring the plants to a soilless nutrient solution
文本阅读题及答案 第6篇
The word "merge" in the passage is closest in meaning to
○ expand
○ separate
○ straighten out
○ combine
What does the discussion in paragraph 1 of runoff channels in the southern highlands suggest about Mars? ○The atmosphere of Mars was once thinner than it is
○Large amounts of rain once fell on parts of
○The river systems of Mars were once more extensive than Earth"
○The rivers of Mars began to dry up about 4 billion years
Paragraph 2: Outflow channels are probably relics of catastrophic flooding on Mars long They appear only in equatorial regions and generally do not form extensive interconnected Instead, they are probably the paths taken by huge volumes of water draining from the southern highlands into the northern The onrushing water arising from these flash floods likely also formed the odd teardrop-shaped "islands" (resembling the miniature versions seen in the wet sand of our beaches at low tide) that have been found on the plains close to the ends of the outflow Judging from the width and depth of the channels, the flow rates must have been truly enormous-perhaps as much as a hundred times greater than the 105 tons per second carried by the great Amazon Flooding shaped the outflow channels approximately 3 billion years ago, about the same times as the northern volcanic plains
The word "relics" in the passage is closest in meaning to
○ remains
○ sites
○ requirements
○ sources
The word "miniature" in the passage is closest in meaning to
○ temporary
○ small
○ multiple
○ familiar
In paragraph 2, why does the author include the information that 105 tons of water flow through the Amazon river per second?
○To emphasize the great size of the volume of water that seems to have flowed through Mars" outflow channels
○To indicate data used by scientists to estimate how long ago Mars" outflow channels were formed
○To argue that flash floods on Mars may have been powerful enough to cause tear-shaped "islands" to form
○To argue that the force of flood waters on Mars was powerful enough to shape the northern volcanic plains
According to paragraph 2, all of the following are true of the outflow channels on Mars EXCEPT:
○They formed at around the same time that volcanic activity was occurring on the northern
○They are found only on certain parts of the Martian
○They sometimes empty onto what appear to have once been the wet sands of tidal
○They are thought to have carried water northward from the equatorial
Paragraph 3: Some scientists speculate that Mars may have enjoyed an extended early Period during which rivers, lakes, and perhaps even oceans adorned its A 20XX Mars Global Surveyor image shows what mission specialists think may be a delta-a fan-shaped network of channels and sediments where a river once flowed into a larger body of water, in this case a lake filling a crater in the southern Other researchers go even further, suggesting that the data provide evidence for large open expenses of water on the early Martian A computer-generated view of the Martian north polar region shows the extent of what may have been an ancient ocean covering much of the northern The Hellas Basin, which measures some 3,000 kilometers across and has a floor that lies nearly 9 kilometers below the basin"s rim, is another candidate for an ancient Martian
All of the following questions about geological features on Mars are answered in paragraph 3 EXCEPT:
○What are some regions of Mars that may have once been covered with an ocean?
○Where do mission scientists believe that the river forming the delta emptied?
○Approximately how many craters on Mars do mission scientists believe may once have been lakes filled with water?
○During what period of Mars" history do some scientists think it may have had large bodies of water?
According to paragraph 3, images of Mars" surface have been interpreted as support for the idea that
○ the polar regions of Mars were once more extensive than they are now
○ a large part of the northern lowlands may once have been under water
○ deltas were once a common feature of the Martian landscape
○ the shape of the Hellas Basin has changed considerably over time
Paragraph 4: These ideas remain Proponents point to features such as the terraced "beaches" shown in one image, which could conceivably have been left behind as a lake or ocean evaporated and the shoreline But detractors maintain that the terraces could also have been created by geological activity, perhaps related to the geologic forces that depressed the Northern Hemisphere far below the level of the south, in which case they have nothing whatever to do with Martian Furthermore, Mars Global Surveyor data released in 20XX seem to indicate that the Martian surface contains too few carbonate rock layers-layers containing compounds of carbon and oxygen-that should have been formed in abundance in an ancient Their absence supports the picture of a cold, dry Mars that never experienced the extended mild period required to form lakes and However, more recent data imply that at least some parts of the planet did in fact experience long periods in the past during which liquid water existed on the
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
○But detractors argue that geological activity may be responsible for the water associated with the
○But detractors argue that the terraces may have been formed by geological activity rather than by the presence of
○But detractors argue that the terraces may be related to geological forces in the Northern Hemisphere of Mars, rather than to Martian water in the
○But detractors argue that geological forces depressed the Northern Hemisphere so far below the level of the south that the terraces could not have been formed by
According to paragraph 4, what do the 20XX Global Surveyor data suggest about Mars?
○Ancient oceans on Mars contained only small amounts of
○The climate of Mars may not have been suitable for the formation of large bodies of
○Liquid water may have existed on some parts of Mars" surface for long periods of
○The ancient oceans that formed on Mars dried up during periods of cold, dry
Paragraph 5: Aside from some small-scale gullies (channels) found since 20XX, which are inconclusive, astronomers have no direct evidence for liquid water anywhere on the surface of Mars today, and the amount of water vapor in the Martian atmosphere is Yet even setting aside the unproven hints of ancient oceans, the extent of the outflow channels suggests that a huge total volume of water existed on Mars in the Where did all the water go? The answer may be that virtually all the water on Mars is now locked in the permafrost layer under the surface, with more contained in the planet"s polar
The word "hints" in the passage is closest in meaning to
○ clues
○ features
○ arguments
○ effects
Paragraph 2: Outflow channels are probably relics of catastrophic flooding on Mars long ■They appear only in equatorial regions and generally do not form extensive interconnected ■Instead, they are probably the paths taken by huge volumes of water draining from the southern highlands into the northern ■The onrushing water arising from these flash floods likely also formed the odd teardrop-shaped "islands" (resembling the miniature versions seen in the wet sand of our beaches at low tide) that have been found on the plains close to the ends of the outflow ■Judging from the width and depth of the channels, the flow rates must have been truly enormous-perhaps as much as a hundred times greater than the 105 tons per second carried by the great Amazon Flooding shaped the outflow channels approximately 3 billion years ago, about the same times as the northern volcanic plains
Look at the four squares [■] that indicate where the following sentence could be added to the
These landscape features differ from runoff channels in a number of
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
There is much debate concerning whether Mars once had
●
●
●
Answer choices
○Mars" runoff and outflow channels are large-scale, distinctive features that suggest that large quantities of liquid water once flowed on
○Although some researchers claim that Mars may once have had oceans, others dispute this, pointing to an absence of evidence or offering alternative interpretations of
○Various types of images have been used to demonstrate that most of Martian surface contains evidence of flowing
○The runoff and outflow channels of Mars apparently carried a higher volume of water and formed more extensive networks than do Earth"s river
○There is very little evidence of liquid water on Mars today, and it is assumed that all the water that once existed on the planet is frozen beneath its
○While numerous gullies have been discovered on Mars since 20XX, many astronomers dismiss them as evidence that Mars once had liquid water
文本阅读题及答案 第7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
文本阅读题及答案 第8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
文本阅读题及答案 第9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。