Scientists at the California Institute of Technology (Caltech) have reported evidence that Mars was warmer and wetter long ago than it is today. The Caltech scientists say they have directly established the temperature of Mars four billion years ago. At least, they established the surface temperature on part of the planet at that time. The researchers say it is the first such evidence to be discovered and presented. The Caltech scientists say carbonate(碳酸盐)minerals formed on Mars at about eighteen degrees Celsius. They reached the finding after studying a meteorite(陨石)that had its beginnings near the Martian surface. Today, the average temperature on Mars is sixty-three degrees below zero Celsius. The finding was reported on the website of the National Academy of Sciences. Caltech Assistant Professor Woody Fischer helped to prepare the report. He says eighteen degrees Celsius is not especially cold or hot. He says this makes the finding extremely interesting. Knowing the temperature can give scientists an idea of the climate on Mars long ago. It can also help them decide whether the planet had liquid water. Spacecraft orbiting Mars have shown what appear to be rivers, lakebeds and mineral deposits. These pictures suggest that, at one time, water did flow there. Mars Rover vehicles and other spacecraft have proved the information.
![](http://img.shitiku.com.cn/uploads/allimg/20191212/20191212200504-28733.png) The meteorite the scientists examined is one of the oldest known rocks in the world. It is called the Allan Hills meteorite. Its name came from the place in Antarctica where it was found in 1984. The meteorite is believed to have blown loose from the Mars" surface when another space rock struck its "home." 小题1:The underlined word “establish” in Paragraph 1 probably means “___________”.A.to set up | B.to make people accept a belief | C.to discover or prove | D.to start having a relationship with others | 小题2:How did the scientists reach the finding?A.By studying Allan Hills meteorite. | B.By using spacecraft orbiting Mars. | C.By studying minerals gathered on Mars. | D.By studying a meteorite on the Martian surface. | 小题3:According to the fourth paragraph, what have spacecraft orbiting Mars done?A.Measuring the temperature of Mars. | B.Taking photos of the surface of Mars. | C.Finding that there is water flowing on Mars. | D.Proving where human beings will probably land on Mars. | 小题4:Where can we most probably read this passage?A.In a biography of scientists. | B.In a geography magazine. | C.In an environment report. | D.In a science report. |
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小题1:C 小题2:A 小题3:B 小题4:D |
试题分析:本文主要说明一个科学报告:许多年前火星比现在更温暖,潮湿。 小题1:猜词题:从第一段最后一句The researchers say it is the first such evidence to be discovered and presented结合前面两句可以说明科学家发现了40亿年前的火星地表的温度的证据。“establish”是discover or prove ,选C 小题2:细节题:从第二段的句子:They reached the finding after studying a meteorite(陨石) that had its beginnings near the Martian surface.及最后一段It is called the Allan Hills meteorite可知科学家是通过研究Allan Hills陨石得到这个发现的。答案选A 小题3:细节题:从第四段倒数第二,三句话These pictures suggest that, at one time, water did flow there. Mars Rover vehicles and other spacecraft have proved the information.可以看出宇宙飞船火星轨道是给火星地表拍照的。B 小题4:文章出处题:从第一段第一句Scientists at the California Institute of Technology (Caltech) have reported evidence that Mars was warmer and wetter long ago than it is today.可知本文主要讲的是一个科学报告,故选D |
核心考点
试题【Scientists at the California Institute of Technology (Caltech) have reported evi】;主要考察你对
题材分类等知识点的理解。
[详细]
举一反三
Henry was not at math. Even when the teacher explained something a second time, he still couldn’t it. “Never mind. I’ll sit the boy who’s the best at ,” Henry thought, “and his answers.” The day of the exam , and Henry sat next to Allan, was at the top of the class in math. Henry copied Allan’s answers his own exam paper. At the end of the exam, the teacher said, “Well, boys and girls, I’ve decided to give a red to the student who got the grade. It’s for me to decide who I’ll give the star to, however, two students, Henry and Allan, got the grade.” After a moment she went on, “ I’ve decided to give the star to this time.” Henry was _ __ when he heard this. He stood and said, “But I got the same grade as Allan, madam.” “That’s .” The teacher said. “However, Allan’s answer to Question 6 was ‘I don’t know.’, but was ‘Nor do I.’ .”
小题1: | A.well | B.best | C.better | D.good |
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小题2: | A.retell | B.understand | C.remember | D.answer |
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小题3: | A.in front of | B.besides | C.behind | D.next to |
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小题4: | A.English | B.Chinese | C.science | D.math |
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小题5: | A.check | B.choose | C.keep | D.copy |
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小题6: | A.ended | B.came | C.over | D.start |
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小题8: | A.never | B.almost | C.sometimes | D.always |
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小题11: | A.least | B.best | C.lowest | D.highest |
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小题12: | A.unusual | B.easy | C.hard | D.important |
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小题13: | A.because | B.though | C.until | D. if |
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小题14: | A.low | B.high | C.different | D.same |
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小题16: | A.nobody | B.Henry | C.Allan | D.anybody |
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小题17: | A.afraid | B.worried | C.pleased | D.angry |
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小题19: | A.wrong | B.true | C.OK | D.all right |
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小题20: | A.yours | B.mine | C.his | D.others’ |
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It"s a fact that we all dream. Some dreams seem to last for hours, others only for seconds. Some of us have strange dreams, some have interesting dreams, and some of us have unpleasant dreams. Tests in the 1980s showed that these dreams occur within 90-minute cycles, each cycle made up of six stages. In the last stage people experience rapid eye movement, known as REM, and it is in this stage that dreaming takes place. Eighty percent of people who were woken during this sixth stage could easily remember their dreams. On the other hand, when during the first five stages (NREM), only seven percent could describe a dream. However, of these same people woken during the first five stages, 74% were able to remember thinking activity, although they would not call it a dream. NerysDee, who has written about dreams in a book called "Your Dreams and What They Mean" says: "Perhaps during NREM sleep we are sorting out our outer mundane problems, but in REM sleep we are dealing with inside matters." She also makes the following statement about 90-minute cycle: It may also prove the reason why insomniacs who wake in the middle of the night find it impossible to get to sleep again for at least an hour and a half. In other words, until they have missed out one complete 90-minute sleep period. 小题1:Which of the following statements about dreams is TRUE?A.Everyone dreams but very few can recall what they dream. | B.Some people have long dreams and others have very short ones. | C.People can only remember unpleasant dreams. | D.More than eighty percent of people can remember their dreams. | 小题2:According to the tests in the 1980s, dreaming takes place______.A.between each 90-minute cycle | B.at any time during 90-minute cycles | C.during the first five stages of 90-minute cycles | D.in the last stage of 90-minute cycles | 小题3:People woken during REM sleep can______.A.hardly remember their dreams | B.easily remember their dreams | C.only remember their dreams | D.partly remember their thinking activity | 小题4:"Insomniacs" are persons who______.A.can always remember their dreams | B.have trouble getting into sleep at night | C.experience rapid eye movement | D.usually wake after each 90-minute sleep period |
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Most parents, I suppose, have had the experience of reading a bedtime story to their children. And they must have how difficult it is to write a children"s book. Either the author has aimed too . , so that the children can"t follow what is in his (or more often, her) story, the story seems to be talking to the readers. The best children"s books are very difficult nor very simple, and satisfy both the who hears the story and the adult who it. Unfortunately, there are in fact books like this, the problem of finding the right bedtime story is not to solve. This may be why many of books regarded as of children"s literature were in fact written for . “Alice"s Adventure in Wonderland” is perhaps the most of this. Children, left for themselves, often the worst possible interest in literature. Just leave a child in bookshop or and he will more willingly choose the books in an imaginative way, or have a look at most children"s comics ( 连环画 ), full of the stories and jokes to which both teachers and right-thinking parents . Perhaps we parents should stop trying to persuade children into our taste in literature. After all children and adults are so that we parents should not expect that they will enjoy the books. So I suppose we"ll just have to compromise(妥协) over that bedtime story.
小题1: | A.hoped | B.realized | C.told | D.said |
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小题3: | A.easy | B.short | C.high | D.difficult |
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小题5: | A.both | B.neither | C.either | D.very |
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小题6: | A.child | B.father | C.mother | D.teacher |
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小题7: | A.hears | B.buys | C.understands | D.reads |
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小题8: | A.few | B.many | C.little | D.much |
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小题9: | A.but | B.however | C.so | D.because |
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小题10: | A.hard | B.easy | C.enough | D.fast |
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小题11: | A.articles | B.work | C.arts | D.works |
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小题12: | A.adults | B.girls | C.boys | D.children |
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小题13: | A.difficult | B.hidden | C.obvious | D.easy |
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小题15: | A.library | B.school | C.home | D.office |
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小题16: | A.read | B.designed | C.printed | D.written |
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小题17: | A.favor | B.interest | C.object | D.read |
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小题18: | A.receiving | B.accepting | C.having | D.refusing |
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小题19: | A.same | B.friendly | C.different | D.common |
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小题20: | A.common | B.average | C.different | D.same |
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A device that stops drivers from falling asleep at the wheel is about to undergo(接受) testing at Department of Transport laboratories and could go on sale within 12 months. The system, called driver Alert, aims to reduce deadly road accidents by 20%--40% that are caused by tiredness. Airline pilots can also use it to reduce the 30% of all pilot-error accidents that are related to fatigue(疲劳). Driver Alert is based on a computerized wristband. The device, worn by drivers or pilots gives out a sound about every four minutes during a car journey. After each sound the driver must respond by squeezing the steering wheel(方向盘). A sensor in the wristband detects this pressing action and measures the time between the sound and the driver’s response. Tiredness is directly related to a driver’s response time. Usually, a watchful driver would take about 400 milliseconds to respond, but once that falls to more than 500 milliseconds, it suggests that the driver is getting sleepy. In such cases the device gives out more regular and louder sounds, showing that the driver should open a window or stop for a rest. If the driver’s response continues to slow down, the sounds become more frequent until a nonstop alarm warns that the driver must stop as soon as possible. The device has been delivered to the department’s laboratories for testing. If these tests, scheduled for six months’ time, are successful, the makers will bring the product to market within about a year. 小题1:How should a driver respond to the sounds from Driver Alert?A.By sounding a warning. | B.By touching the wristband. | C.By checking the driving time. | D.By pressing the steering wheel. | 小题2:We can learn from the text that the driver needs to stop for a break when his response time is ________A.about 400 milliseconds | B.below 500 milliseconds | C.over 500 milliseconds | D.about 4 minutes | 小题3:When the driver gets sleepy while driving, Driver Alert ______.A.moves more regularly | B.stops working properly | C.opens the window for the driver | D.sounds more frequently and loudly | 小题4:According to the text, Driver Alert ______.A.aims to reduce tiredness-related accidents | B.has gone through testing at laboratories | C.aims to prevent drivers from sleeping | D.has been on sale for 12 months |
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The Royal Commission on Environmental Pollution has just published a report on new materials and has looked at the case of nanotechnology(纳米技术), which describes the science of the very small. Nanotechnology covers those man-made materials or objects that are about a thousand times smaller than the microtechnology(微电子技术)we use, such as the silicon chips of computers. Nanotechnology gets its name from the nanometer, which is a billionth of a meter. There are about 600 consumer products already on the market that use nanotechnology. Nanomedicine is also being developed to fight cancer and other fatal diseases. The Royal Commission found no evidence of harm to health or the environment from nanomaterials, but this “absence of evidence” is not being taken as “evidence of absence”. In other words, just because there are no apparent problems, this is not to say that here is no risk now or in the future. The commission is concerned about the pace at which we are inventing and adopting new nanomaterials, which could result in future problems that we are ill-equipped to understand or even find with current testing methods. One of the problems about nanotechnology is that when we make something very small out of a well known material, we may actually change the functionality of that material even if the chemical composition remains the same. Indeed, it is not the particle(颗粒)size that should concern us, but its functionality. Take gold, for example, which is a famously inert (惰性) substance, and valuable because of it. It doesn’t rust or corrode because it doesn’t interact with water or oxygen. However, a particle of gold that is between 2 and 5 nanometers in diameter becomes highly reactive. This is not due to a change in chemical composition, but because of a change in the physical size of the gold particles. How can a change in size result in a change of function? One reason is to do with surface area. Nanoparticles have relatively a much bigger surface area. It is like comparing the surface area of a basketball with the total surface area of many pea-sized balls with the same weight of the single basketball. The pea-sized balls have a surface area many hundreds, indeed thousands of times bigger than the basketball, and this allows them to interact more easily with the environment. It is this increased interactivity that changes their functionality—and makes them potentially more dangerous to health or the environment. 小题1:Why does the writer mention microtechnology in the first paragraph?A.to introduce the topic of nanotechnology | B.to help us better understand nanotechnology | C.to help us know more about microtechnology | D.to compare microtechnology with nanotechnology | 小题2:The example of the “gold” in the last paragraph is intended to show that_________.A.gold is valuable because it is an inert substance | B.an inert substance like gold doesn’t interact with water or oxygen | C.the function of gold is steady because it is an inert substance | D.the function of gold changes when made into something very small | 小题3:Which process explains that there might be risks in nanotechnology? A.expand surface area →increase interactivity → change functionality→cause possible dangers | B.expand surface area → change functionality → increase interactivity →cause possible dangers | C.increase interactivity → expand surface area → change functionality→cause possible dangers | D.increase interactivity → change functionality → expand surface area→cause possible dangers | 小题4:What does the passage mainly focus on?A.the introduction of nanotechnology and its wide use | B.the present use of nanotechnology and its future | C.the potential danger nanotechnology may bring us | D.the proposal to stop nanotechnology due to the potential danger |
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