How the Grand Canyon (大峡谷) was created remains one of the geology’s greatest mys
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How the Grand Canyon (大峡谷) was created remains one of the geology’s greatest mysteries. Some evidence suggests that the process was a gradual one in which the Colorado River (which runs through the canyon) slowly cut deeper and deeper into the ground over millions of years. But volcanic rock samples taken from the canyon now suggest that the canyon was down-cut instead.
Down-cutting is when a flood of water rushes over a landscape (地形) with enough force to cut deeply into the ground and leaves behind a canyon. Such a flood is usually released when a natural or man-made dam (堤坝) bursts.
Robert Webb, a research geologist, says natural dams seem to have formed and broken across the Colorado River several times during the last million years. The dams were built when lava(熔岩) from the eruptions of nearby volcanoes flowed into the river. The lava hardened into hard rocks and blocked the river, causing it to back up and form a lake. Each time the lake grew so huge that it broke the rock dam, releasing a flash flood that furthered the down-cutting process and deepened the canyon.
Down-cutting is not just an earthly event. Satellite photos sent back from Mars suggest that the process has happened there, too, say many other researchers.
The photos, taken by the Mars Global Surveyor, indicate that an enormous lake existed on Mars 3.5 billion years ago. The lake spilled into a large nearby hole. One edge of the hole broke, releasing a flash flood that quickly carved out a grand canyon.
The existence of down-cutting on Mars is just one more piece of evidence that the cold, dry planet was once warm and wet.
小题1:In the past, deep canyons were believed to have formed _______.| A．as a result of a sudden break of volcanoes | | B．due to river flows over millions of years | | C．owing to the burst of artificial dams | | D．thanks to our ancestors’ creative work |
小题2:According to the passage, which of the following statements is TURE?| A．Several volcanoes broke out on Mars directly creating grand canyons. | | B．Several great lakes existed on the upper parts of the Colorado River. | | C．People built high dams on the upper parts of the Colorado River. | | D．The Colorado River crossed the Grand Canyon to form down-cutting. |
小题3:From the last three paragraphs we learn that _______.| A．there are great lakes on Mars | | B．there are active volcanoes on Mars | | C．there might be cities on Mars | | D．there might be life on Mars |
小题4:The passage can be titled as _______.| A．Lakes on Earth and Mars | | B．The Cause of Lake Formation | | C．The Force of Dam Breaking | | D．Canyons—Results of Flood Cutting |
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答案
小题1:B
小题2:B
小题3:D
小题4:D |
解析
试题分析：和以往人们的想法不同的是，这篇文章的作者认为大峡谷的形成是洪水下切侵蚀造成的，主要是上游的湖泊泛滥强大的力量造成了峡谷，文章还介绍在火星也有这种现象。
小题1:细节题：从文章第一段的句子：Some evidence suggests that the process was a gradual one in which the Colorado River (which runs through the canyon) slowly cut deeper and deeper into the ground over millions of years.可知过去深深的峡谷据相信是由于多年的河流造成的，选B
小题2:细节题：从文章第三段的句子：The lava hardened into hard rocks and blocked the river, causing it to back up and form a lake.可知在Colorado 河的上游有几个大湖，选B
小题3:细节题：从文章最后一段的句子：The existence of down-cutting on Mars is just one more piece of evidence that the cold, dry planet was once warm and wet.可知在火星上可能有生命，选D
小题4:标题确定题：从文章的内容和第二段的句子：Down-cutting is when a flood of water rushes over a landscape (地形) with enough force to cut deeply into the ground and leaves behind a canyon.可知这篇文章讲的是峡谷是由洪水下切侵蚀造成的，选D |
举一反三
Is the ‘Go to College’ Message Overdone?
Even in a weak job market, the old college try isn’t the answer for everyone. A briefing paper from the Brookings Institution warns that “we may have overdone the message” on college, senior fellow Isabel Sawhill said.
“We’ve been telling students and their families for years that college is the only way to succeed in the economy and of course there’s a lot of truth to that,” Ms. Sawhill said. “On average it does pay off… But if you load up on a whole lot of student debt and then you don’t graduate, that is a very bad situation.”
One comment that people often repeat among the years of slow job growth has been the value of education for landing a job and advancing in a career. April’s national unemployment rate stood at 7.5%, according to the Labor Department. The unemployment rate for high-school graduates over 25 years old who hadn’t attended college was 7.4%, compared with 3.9% for those with a bachelor’s degree or more education. The difference is even bigger among those aged 16-24. The jobless rate for those with only a high school diploma in that age group is about 20%. At the same time, recent research by Canadian economists cautions that a college degree is no guarantee of promising employment.
Ms. Sawhill pointed out that among the aspects that affect the value of a college education is the field of one’s major: Students in engineering or other sciences end up earning more than ones who major in the arts or education. The cost of tuition and the availability of financial aid are other considerations, with public institutions generally a better financial bargain than private ones.
She suggested two avenues for improving the situation: increasing vocational(职业的)-technical training programs and taking a page from Europe’s focus on early education rather than post-secondary learning. “The European countries put a little more attention to getting people prepared in the primary grades,” she said. “Then they have a higher bar for whoever goes to college—but once you get into college, you’re more likely to be highly subsidized(资助).”
She also is a supporter of technical training—to teach students how to be plumbers, welders and computer programmers—because “employers are desperate” for workers with these skills.
小题1:People usually think that _____.| A．the cost of technical schooling is a problem | | B．one will not succeed without a college degree | | C．technical skills are most important for landing a job | | D．there is an increased competition in getting into a college |
小题2:What does the underlined part “taking a page from” mean?| A．Hearing from. | B．Changing from. | | C．Differing from. | D．Learning from. |
小题3:What can we infer from the passage?| A．Public institutions charge more for education. | | B．European universities are stricter with students. | | C．Students with certain skills are in great demand. | | D．Canadian students prefer to major in engineering. |
小题4:Ms. Sawhill may probably agree that _____.| A．too much stress has been put on the value of college degrees | | B．technical training is more important than college education | | C．a college degree will ensure promising employment | | D．it’s easier for art students to find favorite jobs |
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It’s five minutes before the exam and you are in a state of panic. You just have to pass it, but how? You didn’t even open the book the night before and you hear a voice in your head saying “Cheat, cheat ...” So what are you going to do, ignore it and fail or go for it? It’s a tough decision many students must make.
Most young people believe that cheating is wrong. However, they have cheated at least once in their high school years. So, why do they do it? Are they too lazy to study? Perhaps, it’s not as simple as that. According to some experts, one main reason why students cheat is that they see their friends get away with it. It’s an easy way out. They avoid embarrassment and their parents’ anger for not doing well in an exam. Another reason is that students think it’s OK to cheat if the subject isn’t important for their future career. What’s more, most students have to put up with the pressure of getting into university. They need to get good marks to carry on with their studies. This means that there will always be students who will do anything for a better mark.
It has never been easier to cheat than it is today. With all the technology available, students needn’t cheat by looking over their shoulders anymore. They use mobile phones to send answers to each other during a test. There is also the Internet. With hundreds of websites, students don’t have to worry because they can find lots of material which they can copy and use in projects. There are even tips on the art of cheating in exams.
Obviously, if you get caught cheating, you fail the exam or the subject. But it doesn’t really matter whether you get caught or not. What’s important is that it’s wrong. You mustn’t cheat because cheating is a lie. It deceives (欺骗) people into thinking you know more than you actually do. How can you be proud of something you have achieved through cheating? In the end, it’s not about deceiving your teachers and your parents, but about fooling yourself that you can do something you really can’t.
小题1:The tough decision that many students have to make before an exam is . | A．whether to cheat or not | B．what to do if they fail | | C．how to cheat | D．how to keep calm |
小题2:According to the experts, why do some students cheat?| A．The subjects are important for their future. | B．They are too lazy to study. | | C．Cheating can help them please their parents. | D．Their friends ask them to cheat. |
小题3:The worst thing about cheating is that . | A．you cheat others and yourself | | B．you can get caught and fail | | C．you give others a bad impression | | D．your teacher will inform your parents |
小题4:Which sentence best summarizes the whole text? | A．Cheating can be explained but not excused. | | B．Technology has made cheating easier. | | C．Students cheat to get into university. | | D．Cheating is a social and psychological problem. |
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As a professor I have grown accustomed to the opinion regarding American education. We are repeatedly told that American schools are failing, that colleges are not teaching, and that the students of today are not as good as the students of the past.
There are, of course, problems with the education system. Because of economic inequality some schools are significantly better than others and the ideas of equality of education and equality of opportunity are cruel jokes. However, the mere fact that there are some serious problems does not mean that all the dire claims are true.
One stock (陈腐的) claim is that America has fallen behind the world in education in terms of performance on various tests. While the fact that America is behind other countries is a point of concern, there are at least three points worth considering here. The first is the above-mentioned economic inequality which will tend to result in poorer performance when taking the average for America. The second is that many countries have put considerable effort into improving their education systems and hence it is worth considering that America’s decline is also due to the improvement of others. The third is the matter of the measures— do they, in fact, present an accurate picture of the situation? I am not claiming that the data is bad. I am merely raising a reasonable concern about how accurate our picture of education is at this time.
Another stock claim is that American students are doing badly on standardized tests. While there is clearly value in assessment, it is reasonable to consider whether or not such tests are a proper and adequate measure of education. It is also worth considering whether the puzzle with these tests is itself causing damage to education. That is, as teachers teach for the test and students learn for the test, it might be the case that what is being taught is not what should be taught and what is being learned is not what should be learned.
小题1:According to the professor, many people’s attitude towards American colleges is .| A．negative | B．positive | C．approving | D．indifferent |
小题2:What does the underlined word “dire” in the second paragraph mean? | A．Exact or precise. | B．Extremely serious or terrible. | | C．Fair or objective. | D．Long and boring. |
小题3:Judging by the text ,the claims are centered on .| A．what should be taught in the American classroom | | B．fair judgment of American education | | C．American students’ performance on tests | | D．an accurate picture of American colleges |
小题4:The passage is written mainly to .| A．defend American education | | B．show dissatisfaction with American education | | C．explain why American students do badly on tests | | D．offer advice on American education reform |
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“Enough” with the multivitamins already. That’s the message from experts behind three new studies that tackled an often debated question: Do daily multivitamins多种维生素make you healthier?
“We believe that the case is closed - supplementing(补充) the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful,” concluded the authors of the editorial summarizing the new research papers. They urge consumers to not ‘waste’ their money on multivitamins. “The ‘stop wasting your money’ means that perhaps you’re spending money on things that won’t protect you long term,” editorial co-author, Dr. Edgar Miller said, “What will protect you is if you spend the money on fruits, vegetables, nuts, beans, low fat dairy, and things like that. Exercising would probably be a better use of the money.”
The strong message was based on a review of the findings from three studies that tracked multivitamins link to cancer protection, heart health, and brain and cognitive(认知的) measures. The first study looked at vitamin supplementation’s role in preventing chronic(慢性的) disease. The next study looked at whether long-term use of multivitamins would have any effect on slowing cognitive decline. The third study looked specifically at multivitamins and minerals role in preventing heart attack. “The three studies found no difference in rates of chronic disease, heart attack and the need for hospitalization between vitamin-takers and placebo(安慰剂)-takers.” Dr. Edgar Miller stated.
One expert agreed some nutrient-deficient people may still benefit from multivitamins. “There might be an argument to continue taking a multi(vitamin) to replace or supplement your not healthy diet,” Dr. Edgar Miller added. He also notes that vitamins can benefit people with celiac disease and those who are pregnant.
小题1:This text is likely to be selected from a book of .| A．medicine | B．education | C．food | D．business |
小题2:Which of the following is NOT Dr. Edgar Miller’s opinion according to the passage?| A．Vitamins should not be used for chronic disease prevention. Enough is enough. | | B．Having a balanced diet and exercising would probably be a better way to keep healthy. | | C．The three studies do not provide support for use of multivitamin supplements. | | D．Taking vitamins to replace or supplement your healthy diet is necessary. |
小题3:What can be inferred from the text?| A．Vitamin supplements have proved harmful to the health of adults. | | B．Vitamin supplements are beneficial in certain conditions. | | C．Nowadays taking vitamin supplements is common to most people. | | D．Daily multivitamins will make you healthier. |
小题4:The author’s purpose of writing the text is most likely to___________. .| A．persuade | B．describe | C．inform | D．instruct |
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If your dog looks pleased to see you – it is probably because it loves the particular way you smell.
The odour of a familiar human apparently lingers like perfume in the animal’s brain – where it triggers an instinctive emotional response, research published yesterday reveals.
Our scent acts on a part of the canine brain associated with reward and the strongest reactions are produced by humans that pets know best, say scientists in America.
Gregory Berns, of Emory University in Atlanta, said: ‘While we might expect that dogs should be highly tuned to the smell of other dogs, it seems that the “reward response” is reserved for their humans.
"When humans smell the perfume or cologne of someone they love, they may have an immediate, emotional reaction that"s not necessarily cognitive.
"Our experiment may be showing the same process in dogs. But since dogs are so much more olfactory(嗅觉的) than humans, their responses would likely be even more powerful than the ones we might have.
"It"s one thing when you come home and your dog sees you and jumps on you and licks you and knows that good things are about to happen.
"In our experiment, however, the scent donors were not physically present.
Why do animals avoid pylons? Because they emit terrifying flashes of light that are INVISIBLE to humans.
Dolphins use sponges to protect their sensitive noses while foraging for food on the sea floor
"That means the canine brain responses were being triggered by something distant in space and time. It shows that dogs" brains have these mental representations of us that persist when we"re not there."
The university’s experiment - the first of its type - involved 12 dogs of various breeds who underwent brain scans while five different scents were placed in front of them.
The scent samples came from the subject itself, a dog the subject had never met, a dog that lived in the subject"s household, a human the dog had never met, and a human that lived in the subject"s household.
The familiar human scent samples were taken from someone else from the house other than the handlers during the experiment, so that none of the scent donors were physically present.
The results showed that all five scents elicited a similar response in parts of the dogs" brains involved in detecting smells. Responses were significantly stronger for the scents of familiar humans, followed by that of familiar dogs.
The findings, which were published in the journal Behavioural Processes, showed that dogs reacted strongest to the scent of a familiar human even when they were not there.
Pets trained as help or therapy dogs showed greater brain activity than the other dogs in the test.
Researchers say the findings could improve the way animals who assist wounded veterans or disabled people are selected.
小题1:Why does your dog look pleased to see you ?| A．because your dog wants to play with you | | B．because your dog is hungry | | C．because your dog wants to attract your attention | | D．because your dog loves the particular way you smell. |
小题2:What’s the purpose of Emory university’s experiment ?| A．To study dog’s reaction while five different scents were placed in front of them. | | B．To learn how to get along well with dogs | | C．To know how to tell the difference between dogs | | D．To improve the way animals who assist wounded veterans or disabled people are selected. |
小题3:According to the passage, a dog will be most interested in____.| A．familiar dogs | | B．a human the dog had never met | | C．a dog the dog had never met | | D．familiar humans |
小题4:Which of the following is true according to the passage?| A．The dog’s olfactory responses would likely be even more powerful than the ones we might have. | | B．In our experiment, the scent donors were physically present. | | C．Dogs reacted strongest to the scent of a familiar human even when they were there. | | D．Dog’s brain responses were not being triggered(引发) by something distant in space and time. |
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