理工B

考试试题

[多选题]共用题干 InflationBusiness and government leaders also consider the inflation rate to be an important general indicator. Inflation is a period of increased spending that causes rapid rises in prices.______(51) your money buys fewer goods so that you get______(52)for the same amount of money as before,inflation is the problem.There is a general rise______(53)the price of goods and services.Your money buys less.Sometimes people describe inflation as a time when"a dollar is not worth a dollar anymore".Inflation is a problem for all consumers.People who live on a fixed income are hurt the ______(54).Retired people,for instance,cannot count on an increase in income as prices rise. Elderly people who do not work face serious problems in stretching their incomes to______(55)their needs in time of inflation.Retirement income______(56)any fixed income usually does not rise as fast as prices.Many retired people must cut their spending to______(57)rising prices.In many cases they must stop______(58)some necessary items,such as food and clothing. Even ______(59)working people whose incomes are going up,inflation can be a problem. The ______(60)of living goes up,too.People who work must have even more money to keep up their standard of living. Just buying the things they need costs more.When incomes do not keep ______(61)with rising prices,the standard of living goes down.People may be earning the same amount of money,but they are not living as well because they are not able to buy as many goods and services.Government units gather information about prices in our economy and publish it as price indexes ______(62)the rate of change can be determined.A price index measures changes in prices using the price for a______(63)year as the base.The base price is set at 100,and the other prices are reported as a______(64)of the base price.A price index makes______(65)possible to compare current prices of typical consumer goods,for example,with prices of the same goods in previous years. _________(57)
[多选题]共用题干 Have You Filled up the Form?Of all things in the world,I most dislike filling up forms;in fact,I have a______(51)horror of it. Applying for a living license,______(52)for an evening course,booking a holiday abroad一everything nowadays seem to involve______(53)information about one's personal life and habits that has little or nothing to do with the matter______(54)hand.When applying for a job,it may be______(55)some obscure interest to a______(56)employer to learn that I collect stamp or had measles as a child,but why should he conceivably want to know that my father was a tobacconist who died in 1988?The authorities who______(57)one to fill up forms,frequently demand answers to questions that one would hesitate to put______(58)one's intimate friends.The worst of it is that, when______(59)with such questions,my mind goes blank.Have I ever suffered from a serious illness?My mother always assured me I was"delicate".Do I suffer from any personal defects? Well,I wear contact lenses and my upper teeth are not my own,but perhaps the word"defects"______(60)to my character. Am I supposed to______(61)that I like gambling,and find it difficult to get up in the morning? Both of them are true.Of all,I think job applications are the worst,"education”一previous experience一post heldgive______(62)…Terrified by the awful warning about giving false______(63)which appear at the bottom of the form,I struggle to remember what exams I passed and how long I worked for what firms.______(64)hard I try,there always seems to be a year or two for which I cannot satisfactorily account and which I am certain,if left______(65),will give the impression that I was in prison or engaged in some occupation too dubious to mention. _________(64)
[多选题]共用题干 Look After Your VoiceOften speakers at a meeting experience dry mouths and ask for a glass of water. You can solve the problem by activating the saliva in your mouth.First gently bite the edges of your tongue with your teeth.Or,press your entire tongue to the bottom of your mouth and hold it there until the saliva flows.Or you can imagine that you are slicing a big juicy lemon and sucking the juice.Before you begin your talk,be kind to your voice,Avoid milk or creamy drinks which dry your throat. Keep your throat wet by drinking a little sweetened warm tea or diluted fruit juice.If you sense that you are losing your voice,stop talking completely.In the meantime,do not even talk in a low voice.Save your voice for your health.You may feel foolish using paper to write notes,but the best thing you can do is to rest your voice.If it is necessary,perhaps you can get some advice from a professional singer.What about drinking alcohol to wet your throat?I advice you not to touch alcohol before speaking. The problem with alcohol is that one drink gives you a little confidence.The second drink gives you even more confidence.Finally you will feel all-powerful and you will feel you can do everything,but in fact your brain and your mouth do not work together properly.Save the alcohol until after you finish speaking.Perhaps you want to accept the advice,but you may wonder if you can ever change the habits of a lifetime .Of course you can.Goethe,who lived before indoor skating rinks or swimming pools,said,“We learn to skate in the summer and swim in the winter”.Take this message to heart and give yourself time to develop your new habits.If you are willing to change,you will soon be able to say that you will never forget these techniques because they became a part of your body. The writer cites Goethe to prove that one can change one's habits.
[多选题]共用题干 Plants in DesertOnly special plants can survive the terrible climate of a desert,for these are regions where the annual range of the soil temperature can be over 75℃.Furthermore,during the summer there are few clouds in the sky to protect plants from the sun's ray.Another problem is the fact that there are frequently strong winds that drive small,sharp particles of sand into the plants,tearing and damaging them.The most difficult problem for all forms of plant life,however,is the fact that the entire annual rainfall occurs during a few days or weeks in spring.Grasses and flowers in desert survive from one year to the next by existing through the long,hot,dry season in the form of seeds.These seeds remain inactive unless the right amount of rain falls.If no rain falls,or if insufficient rain falls,they wait until the next year,or even still the next.Another factor that helps these plants to survive is the fact that their life cycles are short.By the time the water from the spring rains disappears-just a few weeks after it falls-such plants no longer need any.The perennials(多年生植物)have special features that enable them to survive as plants for several years.Thus,nearly all desert perennials have extensive root systems below ground and a small shoot system above ground.The large root network enables the plant to absorb as much water as possible in short time.The small shoot system,on the other hand,considerably limits water loss by evaporation(蒸发).Another feature of many perennials is that after the rainy season they lose their leaves in preparation for the long,dry season,just as trees in wetter climates lose theirs in preparation for the winter.This reduces their water loss by evaporation during the dry season.Then,in next rainy season,they come fully alive once more,and grow new branches,leaves and flowers,just as the grasses and flowers in desert do. Desert perennials,lose their leaves after the rainy season just as trees in wetter climates lose theirs because winter arrives,but the reasons for this feature are different.
[多选题]共用题干 Avalanche and Its SafetyAn avalanche is a sudden and rapid flow of snow,often mixed with air and water,down a mountainside .Avalanches are______(51)the biggest dangers in the mountains for both life and property.All avalanches are caused by an over-burden of material,typically snowpack,that is too massive and unstable for the slope______(52)supports it. Determining the critical load,the amount of over-burden which is______(53)to cause an avalanche,______(54)a complex task involving the evaluation of a number of factors.Terrain slopes flatter than 25 degrees or steeper than 60 degrees typically have a low ______(55)of avalanche .Snow does not______(56)significantly on steep slopes;also, snow does not______(57)easily on flat slopes.Human-triggered avalanches have the greatest incidence when the snow's angle of rest is______(58)35 and 45 degrees;the critical angle, the angle at which the human incidence of avalanches is greatest,is 38 degrees.The rule of thumb is:A slope that is______(59)enough to hold snow but steep enough to ski has the potential to generate an avalanche,regardless of the angle.Additionally,avalanche risk increases with ______(60);that is,the more a slope is disturbed by skiers,the more likely it is that an avalanche will occur.Due to the complexity of the subject,winter travelling in the backcountry is never 100% safe .Good avalanche safety is a continuous______(61),including route selection and examination of the snowpack,weather______(62),and human factors.Several well-known good habits can also______(63)the risk .If local authorities issue avalanche risk reports,they should be considered and all warnings should be paid______(64)to. Never follow in the tracks of others without your own evaluations;snow conditions are almost certain to have changed since they were made .Observe the terrain and note obvious avalanche paths where plants are ______(65)or damaged .Avoid travelling below others who might trigger an avalanche. 51._________
[多选题]共用题干 Smoking can Increase Depressive Symptoms in TeensWhile some teenagers may use cigarettes to "self-medicate"(自我治疗)against the blues(忧郁),sci- entists at the University of Toronto and the University of Montreal have found that smoking may actually ______________(51)depressive symptoms in some teens."This observational study is one of the few to examine the perceived ______________(52)benefits of smoking among teens,"says lead researcher Michael Chaiton,a research associate at the Ontario Tobacco Research Unit of the University of Toronto."_______________(53)cigarettes may appear to have self-medicating effects or to improve mood,in the long_______________(54)we found that teens who started to smoke reported higher depressive symptoms."As part of the study,some 662 high school teenagers completed up to 20 questionnaires about their useof cigarettes to ______________(55)mood.Secondary schools were selected to provide a mix of French andEnglish participants,urban and rural schools,and schools ______________(56)in high,moderate and low so-cioeconomic neighbourhoods.Participants were divided into three______________ (57):never smokers;smokers who did not use ciga-rettes to self-medicate,improve mood or physical______________ (58);smokers who used cigarettes to self-medicate.Depressive symptoms were measured using a scale that asked how often participants felt too tiredto do things;had______________ (59)going to sleep or staying asleep;felt unhappy,sad,or depressed;felt hopeless about the future;felt anxious or tense;and worried too much about things." Smokers who used cigarettes as mood______________( 60 ) had higher risks of elevated(提升)depres-sive symptoms______________ (61)teens who had never smoked,"says co-researcher Jennifer O'Loughlin,aprofessor at the University of Montreal Department of Social and Preventive Medicine."Our study found that teen smokers who reported emotional benefits from smoking are_______________(62)higher risk of developing depressive symptoms."The______________ (63)between depression and'smoking exists______________(64)among teens that usecigarettes to feel better."It's ______________(65)to emphasize that depressive symptom scores were higher among teenagers who reported emotional benefits from smoking after they began to smoke,"says Dr. Chaiton. _________(52)
[多选题]共用题干 第二篇FearFear is something that always remains in our heart. We can never eliminate fear from our life. Fear of failing in exams which can make a negative impact in someone's career,and fear of speaking in public where majority of human think that people will make fun of them.Fear of not being liked, fear of storms and floods,fear of being alone and many others are all very common examples of fear.Fear can also affect our physical beings like pounding of the heart,rapid pulse rate,tense muscles,dryness of the throat,churning in the stomach,confusion,fainting,and the inability to concentrate.These things are also very common.Fear is only hidden somewhere inside our bodies, pushing us to work hard and moving us forward to overcome our weaknesses.Fear is the way to our success.I had a very bad experience of fear in my childhood days.My father told me that if I got bad grades another time in my school exams,then he would kick me out of his home and would never allow me to come back again.This sentence of my father stuck in my mind because one of my friends in school at that time recently became homeless.He belonged to a poor family,and his father had lost a big amount of money in a small business near his home.So, the problems he was facing from homelessness made me work hard in my exams;otherwise,I might have been kicked out of home by my father.Fear sometimes can be motivating,and help us to do those things which we think and believe that we can never do.One of the most common fear inducing activities,for example,is swimming. This is primarily caused by most of us not having a background in swimming and only taking it up because it is part of the sport. Additionally,most humans are uncomfortable in the water as a general rule because of the fear of drowning. This fear of drowning is innately strong,and similar common or strong fears tend not to exist when it comes to cycling or running because they are land based activities.
[多选题]共用题干 第二篇Bullying at school can have serious and harmful negative effects.Because it causes such a problem for many schools,it is important that schools take the appropriate action to minimize its harmful effects.One of the most influential steps that a school can take against bullying is to research and develop a firm understanding of the specific types of bullying the students at the school are facing. Administrators should conduct monthly surveys that ask students about their experiences with bullying, such as whether they were bullied in the past month,whether they witnessed bullying and issues that they think the school administrators should have known about. Administrators should also survey the school's teachers to find out what they know about bullying.Another step that a school administration can take to prevent bullying is to train its teachers, administrators and students' parents about bullying. Hold seminars in your school district to teach parents about ways to communicate with their children if they are bullied at school.Conduct workshops with professional speakers or psychology experts about recognizing the signs of bullying in the classroom for teachers and administrators in your school district.Create newsletters for parents about detail strategies your school is taking to combat bullying or discuss new research on bullying in schools.Last but not least school administrators,teachers and school board members should work together to create a disciplinary plan to use when situations of bullying arise.Make teachers work together in groups to discuss the strategies that they use for dealing with bullying in their individual classrooms.Developing a plan when bullying arises is important in helping students realize that they will face consequences if they choose to bully their peers.Having a disciplinary system in place can help prevent bullying before it even begins. In order to research bullying,what should administrators ask students about?
[多选题]共用题干 Microchip Research Center CreatedA research center has been______(51)in this Far Eastern country to develop advanced microchip production technology.The center,which will start out with about US$14 million,will help the country develop its chip industry without always depending on imported technology.The center will make use of its research skills and______(52)to develop new technology for _______(53)chip plants.The advent of the center will possibly free the country from the_______(54) that it is always buying almost-outdated technologies from other countries,said the country's flagship chipmaker.______(55),chip plants in this country are in a passive situation because many foreign governments don't allow them to______(56)the most advanced technologies,fearing they will be used for______(57) purposes.Moreover,the high licensing fees they have to pay to technology providers are also an important _(58)for their decision of self-reliance.As mainstream chip production technology______(59)from one generation to the next every three to five years,plants with new technology can make more powerful chips at lower costs,while plants with______(60)equipment,which often cost billions of dollars to build,will be______(61)by the maker.More than 10 chip plants are being built,each costing millions of US dollars.The majority of that money goes to overseas equipment______(62)and technology owners-mainly______(63)Japan and Singapore.Should the new center play a major role in improving the situation in the industry,the country admits the US $14 million investment is still rather small.This country is developing______(64)technologies.Most of the investment will be spent on setting_______(65)with technology and intellectual property owners. 59._________
[多选题]共用题干 第三篇Eye-tracker Lets You Drag and Drop Files with a GlanceBored of using a mouse?Soon you'11 be able to change stuff on your computer screen-and then move it directly onto your smartphone or tablet(平板电脑)-with nothing more than a glance.A system called EyeDrop uses a head-mounted eye tracker that simultaneously records your field of view so it knows where you are looking on the screen.Gazing at an object-a photo,say-and then pressing a key,selects that object.It can then be moved from the screen to a tablet or smartphone just by glancing at the second device,as long as the two are connected wirelessly."The beauty of using gaze to support this is that our eyes naturally focus on content that we want toacquire,"says Jayson Turner,who developed the system with colleagues at Lancaster University,UK.Turner believes EyeDrop would be useful to transfer an interactive map or contact information from a public display to your smartphone or tablet for sharing photos.A button needs to be used to select the object you are looking at otherwise you end up with the"Midas touch"(点石成金)effect, whereby everything you look at gets selected by your gaze, says Turner."Imagine if your mouse clicked on everything it pointed at,"he says.Christian Holz,a researcher in human-computer interaction at Yahoo Labs in Sunnyvale,California, says the system is a nice take on getting round this fundamental problem of using gaze-tracking to interact."EyeDrop solves this in a slick(灵巧的)way by combining it with input on the touch devices we carry with us most of the time anyway and using touch input as a clutching mechanism,"he says."This now allows users to seamlessly(无缝地)interact across devices far and close in a very natural manner."While current eye-trackers are rather bulky,mainstream consumer devices are not too far away.Swedish firm Tobii is developing gaze-tracking technology that can be installed in laptops and tablets and is expected to be available to buy next year.And the Google Glass headset is expected to include eye-tracking in the future.Turner says he has also looked at how content can be cut and pasted or drag-and-dropped using a mix of gaze and taps on a touchscreen.The system was presented at the Conference on Mobile and Ubiquitous Multimedia in Sweden,last week. What is Turner likely to study next?
[多选题]共用题干 第二篇Archive Gallery : The Best of Bionics(仿生学)Humans might be the most highly-evolved species on the planet,but most animals possess skills we can only dream of having. Imagine how much electricity we could save if we could see in the dark the way catsdo. Imagine leaping from tree to tree like a monkey. Giraffes(长颈鹿),which are otherwise calm and good- natured,sleep only 4.6 hours a day.We realized a long , long time ago that nature provides the best blueprint(蓝图)for invention. We ' ve borrowed canals from beavers(河狸)and reflectors from cat's eyes. Although the words"bionics"became popular only after the l960s,history shows that nature has always provided ideas on solving everyday prob- lems. Our archives(档案)don't go back to the time of Leonardo da Vinci and his bird-like flying machines,but we can take you to the late 19th century,where we applied those same principles for building our first practical airplanes.To prepare for their flight at Kitty Hawk,the Wright brothers studied the movements of pigeons to fingureout how they stayed high up when they were heavier than air. Their success inspired scores of successors to improve on the airplane by studying various aspects of nature.One of Orville Wright's pupils caught and stuffed seagulls to examine their wingspan.Meanwhile,two French inventors examined spinning sycamore(美 国梧桐)seeds in an effort to apply those same motions , reversed , to a helicopter.Some examples are more obvious than others.The outside of the airplane designed by the WrightDrotliers looks like a minimalistic(简单抽象艺术)structure. On the other hand , Barney Connett ' s fish iubmarine(潜水艇)actually looks like a fish.Some bio-inspired concepts have yet to be invented.In the l960s,the US Army commissioned several iniversity professors to conduct research on the motor skills of animals in hope of applying those same abili- ies to tanks. Tanks that run like horses or jump like grasshoppers(蚂炸)一sounds shocking,doesn't it? 3ut imagine how life would change if we could achieve that. Which of the following can be found in the archive gallery?
[多选题]共用题干 ADHD Linked to Air PollutantsChildren have an increased of attention problems,seen as early as grade school,if their no-ses inhaled(吸入)a certain type of air pollution when they were pregnant. That's the finding of a new study.Released when things aren't burned completely,this pollution is known as polycyclic aromatic hydrocarbons,or PAHs.The biggest sources of these PAHs:the burning of fossil fuels, wood and trash.Frederica Perera works at Columbia University's Mailman School of Public Health in New York City.She researches how exposure to things in the environment affects children's health.In a new study,she and her team studied the exposure to air pollution of 233 nonsmoking pregnant women in New York City. Because burning tobacco can spew(排放)PAHs into the air and lungs, Perera's team focused on nonsmokers. The researchers wanted to probe(探查)other sources of PAHs,ones that's would have been hard for an individual to avoid.The team started by testing the blood of each woman during pregnancy.The reason:Any PAHs in a woman's blood would also be available to the baby in her womb.Nine years later,the researchers investigated signs of attention problems in those children,now age 9 .They asked each child's mother a series of questions.These included whatever her child had problems doing things that needed sustained(长期的)mental effort, such as homework or games with friends. The sci-entists also asked if the kids had trouble following instructions or made frequent,careless mis-takes .All of these can be symptoms of a disorder called Attention Deficit Hyperactivity Disorder, or ADHD.About one in U.S.children has ADHD.Among the women studied,traffic and home heating were the primary sources of air pollution exposure,Perera and her team suspect. Some of these women had low levels of PAHs in their blood .Others had high levels.Those with high levels were five times as likely to have children who showed attention problems by age 9 .The new findings were published November 5 in the journal PLOS ONE. Kids with ADHD commonly fail in school.
[多选题]共用题干 Electromagnetic Energy1 White light seems to be a combination of all colors.The energy that comes from a source of light is not limited to the kind of energy you can see.Heat is given off by a flame or an electric light.On a cloudy day it is possible to get a sunburn even though you feel cool.Visible light and the kinds of energy that produce warmth and sunburn are examples of electromagnetic energy.2 The sun is 93 million miles from the earth.Yet we can use energy from the sun because electromagnetic energy travels through space.3 Many other kinds of energy are also types of electromagnetic energy.Radio,television,and radar signals travel from transmitters to receivers as low-energy electromagnetic waves.Infrared(红外线的)radiation is an electromagnetic wave.When it is absorbed by matter,heat is produced.Waves of infrared and visible light have more energy than waves of radio,television,or radar.Ultraviolet rays(紫外线)and X-rays are electromagnetic waves with even greater amounts of energy.Infrared radiation is used in cooking food and heating buildings. Sunlight and electric lights are part of our requirements for normal living.Ultraviolet radiation is useful in killing certain disease organisms.X-rays and gamma rays have so much energy that they travel through solid objects. They can be used to detect and treat cancer.X-rays are used in industry to find hidden cracks in metal,and in medicine to reveal broken bones.4 Usually we use electricity to generate electromagnetic energy.The source of most of our energy is the sun.Heat from the sun causes water to evaporate.When the water falls to the earth as rain,some of it is trapped behind dams and then used to operate electric generators.Other generators are powered by coal,but the energy stored in coal came from the sun,too.5 Until recently,the source of the tremendous amount of energy given off by the sun was a puzzle.If the sun depended on chemical reactions,it would have used up all its energy long ago.Experiments with electromagnetic radiation led to the theory that mass can be converted into energy.About forty years after the theory was proposed , nuclear energy was harnessed(利用)by man.Chemical energy comes from electron (电子)rearrangement.Nuclear energy comes from a change in the nucleus of an atom.Compared with chemical reactions,nuclear reactions release millions of times more energy per pound of fuel.We now believe that the sun's energy comes from the nuclear reactions in which hydrogen is changed into helium(氦).6 Nuclear energy is beginning to compete with coal as an economical source of'power to generate electricity.It is also being used to operate engines in large ships.Scientists continue to seek new and better methods of obtaining and using energy. Paragraph 3______
[多选题]共用题干 第二篇The American IndustryA history of long and effortless success can be a dreadful handicap,but if properly handled,it may become a driving force.When the United States entered just such a glowing period after the end of the Second World War,it had a market eight times larger than any competitor,giving its industries unparalleled economies of scale.Its scientists were the world's best,its workers the most skilled.America and Americans were prosperous beyond the dreams of the Europeans and Asians whose economies the war had destroyed.It was inevitable that this primacy should have narrowed as other countries grew richer. Just as inevitably,the retreat from predominance proved painful.By the mid-1980s Americans had found themselves at a loss over their fading industrial competitiveness.Some huge American industries, such as consumer electronics,had shrunk or vanished in the face of foreign competition.By 1987 there was only one American television maker left,Zenith.(Now there is none:Zenith was bought by South Korea's LG Electronics in July.)Foreign-made cars and textiles were sweeping into the domestic market. America's machine-tool industry was on the ropes.For a while it looked as though the making of semiconductors,which America had which sat at the heart of the new computer age, was going to be the next casualty.All of this caused a crisis of confidence.Americans stopped taking prosperity for granted.They began to believe that their way of doing business was failing,and that their incomes would therefore shortly begin to fall as well. The mid-1980s brought one inquiry after another into the causes of America's industrial decline.Their sometimes sensational findings were filled with warnings about the growing competition from overseas.How things have changed!In 1995 the United States can look back on five years of solid growth while Japan has been struggling. Few Americans attribute this solely to such obvious causes as a devalued dollar or the turning of the business cycle.Self-doubt has yielded to blind pride."American industry has changed its structure,has gone on a diet,has learnt to be more quick-witted,"according to Richard Cavanagh,executive dean of Harvard's Kennedy School of Government,"It makes me proud to be an American just to see how our businesses are improving their productivity,"says Stephen Moore of the Cato Institute,a think-tank in Washington,DC.And William Sahlman of the Harvard Business School believes that people will look back on this period as"a golden age of business management in the United States." What can be inferred from the passage?
[多选题]共用题干 第二篇Bullying at school can have serious and harmful negative effects.Because it causes such a problem for many schools,it is important that schools take the appropriate action to minimize its harmful effects.One of the most influential steps that a school can take against bullying is to research and develop a firm understanding of the specific types of bullying the students at the school are facing. Administrators should conduct monthly surveys that ask students about their experiences with bullying, such as whether they were bullied in the past month,whether they witnessed bullying and issues that they think the school administrators should have known about. Administrators should also survey the school's teachers to find out what they know about bullying.Another step that a school administration can take to prevent bullying is to train its teachers, administrators and students' parents about bullying. Hold seminars in your school district to teach parents about ways to communicate with their children if they are bullied at school.Conduct workshops with professional speakers or psychology experts about recognizing the signs of bullying in the classroom for teachers and administrators in your school district.Create newsletters for parents about detail strategies your school is taking to combat bullying or discuss new research on bullying in schools.Last but not least school administrators,teachers and school board members should work together to create a disciplinary plan to use when situations of bullying arise.Make teachers work together in groups to discuss the strategies that they use for dealing with bullying in their individual classrooms.Developing a plan when bullying arises is important in helping students realize that they will face consequences if they choose to bully their peers.Having a disciplinary system in place can help prevent bullying before it even begins.
[多选题]共用题干 Learn About Noble Gases(惰性气体)1 Have you ever ridden on a balloon?Many tourist spots offer balloon rides in order for people to see the beauty of a place from above.A balloon contains a noble gas called helium(氦).Formerly,balloons con- tamned hydrogen but hydrogen is very flammable and dangerous when uncontrolled.Therefore,people shifted to helium,which is safer. Helium is safe because it has the properties of the noble gases.2 People once believed that noble gases couldn't chemically react at all.For this reason,they were called inert gases(惰性气体).They were also listed under Group 0 in the old periodic table because scien- tists believed that the gases have zero valence(价)electrons in their outer shell.This was later proven to be untrue when some noble gas compounds were discovered.3 The gases are elements,which share similar properties.These properties include being monoatomic, colorless,odorless,being able to conduct electricity,and having low chemical reactivity.Noble gases include helium,neon,argon,krypton,xenon and radon.These are all found in Group 18,in the right most column of the periodic table.If you look at the periodic table,you will notice that these elements are the only ones which do not have a charge. Helium has the lowest molecular(分子的)weight while radon is the heaviest.4 Remember that chemical reactions occur because atoms have valence electrons,which are electrons in their outer shell.When the outer shell is"unfilled"or the required number of electrons is not yet corn- plete,the atom is more reactive.Noble gases have a full outer shell,meaning that they have complete elec- trons in their outer shell.This complete number varies.For instance,the outer shell of helium has 2 valence electrons while the outer shell of xenon has 8 electrons.Nowadays,there remains to be a few noble gases because of the low chemical reactivity of these said gases.5 because of their properties,noble gases have many important applications.They are widely used in medicine and industries. For instance , liquid helium is used for superconducting magnets(磁体).These magnets are very important in physics and medicine.When a doctor suspects that a person's brain has been damaged,he might request for Magnetic Resonance Imaging(MRI).MRI allows the doctor to"see"the brain,without operating on the patient. Paragraph 2 ____________
[多选题]共用题干 第一篇Approaches to Understanding IntelligencesIt pays to be smart,but we are not all smart in the same way.You may be a talented musician,but you might not be a good reader.Each of us is different.Psychologists disagree about what is intelligence and what are talents or personal abilities.Psychologists have two different views on intelligence.Some believe there is one general intelligence.Others believe there are many different intelligences.Some psychologists say there is one type of intelligence that can be measured with IQ tests.These psychologists support their view with research that concludes that people who do well on one kind of test for mental ability do well on other tests.They do well on tests using words,numbers,or pictures.They do well on individual or group tests,and written or oral tests.Those who do poorly on one test,do the same on all tests.Studies of the brain show that there is a biological basis for general intelligence.The brains of intelligent people use less energy during problem solving.The brain waves of people with higher intelligence show a quicker reaction.Some researchers conclude that differences in intelligence result from differences in the speed and effectiveness of information processing by the brain.Howard Gardner,a psychologist at the Harvard School of Education,has four children.He believes that all children are different and shouldn't be tested by one intelligence test.Although Gardner believes general intelligence exists,he doesn't think it tells much about.the talents of a person outside of formal schooling.He thinks that the human mind has different intelligences.These intelligences allow us to solve the kinds of problems we are presented with in life.Each of us has different abilities within these intelligences.Gardner believes that the purpose of school should be to encourage development of all of our intelligences.Gardner says that his theory is based on biology.For example,when one part of the brain is injured,other parts of the brain still work.People who cannot talk because of brain damage can still sing.So,there is not just one intelligence to lose.Gardner has identified 8 different kinds of intelligence:linguistic,mathematical,spatial, musical , interpersonal,intrapersonal , body-kinesthetic(身体动觉的),and naturalistic.
[多选题]共用题干 The Greatest Mystery of WhalesThe whale is a warm-blooded,air-breathing animal,giving birth to its young alive,sucking them-and, like all mammals,originated on land.There are many______(51)of this.Its front flippers(鳍状肢), used for steering and stability,are traces of feet.Immense strength is______(52)into the great body of the big whales,and in fact most of a whale's body is one gigantic muscle.The blue whale's pulling strength has been estimated______(53) 400 horsepower.One specimen was reported to have towed(拖)a whaling vessel for seven hours at the ______(54)of eight knot(节).An angry whale will______(55).A famous example of this was the fate of Whaler Essex, ______(56)was sunk off the coast of South America early in the last century.More recently,steel ships have______( 57 ) their plates buckled(使弯曲)in the same way.Sperm whales(抹香鲸)were known to seize the old-time whaleboats in their jaws and crush them.The greatest______(58)of whales is their diving ability.The sperm whale dives to the bottom for his______( 59 ) food , the octopus(章鱼).In that search he is known to go as far down as 3 , 200 feet, where the______(60)is 1,400 pounds to a square inch.Doing so he will______(61) underwater as long as one hour.Two special skills are involved in this storing up enough______(62) (all whales are air-breathed)and tolerating thern great change in pressure.Just how he does it scientists have not______(63).It is believed that some of the oxygen is stored in a special ______(64)of blood vessels,rather than just held in the lungs.And it is believed that a special kind of oi1 in his head is some sort of a compensating mechanism that______(65)adjusts the internal pressure of his body.But since you can't bring a live whale into the laboratory for study,no one knows just how these things work. 65._________
[多选题]共用题干 Voice Your Opinion一Change is Needed in Youth SportsEverywhere you look,you see kids bouncing。basketball or waving a tennis racquet(网球拍).Andthese kids are getting younger and younger. In some countries,children can compete on basketball,base- ball,and volleyball teams starting at age nine._____________ (46)And swimming and gynmastics classes begin at age four, to prepare children for competition.It's true that a few of these kids will develop into highly skilled athletes and may even become members of the national Olympic teams._____________ (47)This emphasis on competition in sports is having serious negative effects.Children who get involved in competitive sports at a young age often grow tired of their sport. Many parents pressure their kids to choose one sport and devote all their time to it._____________ (48)But 66 per- cent of the young athletes wanted to play more than one sport一for fun.Another problem is the pressure imposed by over-competitive parents and coaches. Children are not naturally competitive. In fact,a recent study by Paulo David found that most children don' t even understand the idea of competition until they are seven years old._____________ (49)The third,and biggest,problem for young athletes is the lack of time to do their homework,have fun, be with friends一in short,time to be kids. When they are forced to spend every afternoon at sports practice, they often start to hate their chosen sport. A research found that 70 percent of kids who take part in competi- tive spoils before the age of twelve quit before they turn eighteen._____________(50) Excessive competitive sports take away all the enjoyment.Need to remember the purpose of youth sportsweto give kids a chance to have developing, strong, healthy bodies. __________(48)
[多选题]共用题干 Women's minds work differently from men's.At least,that is what most men are convinced of. Psychologists view the subject either as a matter of frustration or a joke.Now the biologists have moved into this minefield,and some of them have found that there are real differences between the brains of men and women.But being different,they point out hurriedly,is not the same as being better or worse.There is,however,a definite structural variation between the male and female brain.The difference is in a part of the brain that is used in the most complex intellectual processes一the link between the two halves of the brain.The two halves are linked by a trunk line of between 200 and 300 million nerves,the corpus callosum.Scientists have found quite recently that the corpus callosum in women is always larger and probably richer in nerve fibres than it is in men.This is the first time that a structural difference has been found between the brains of women and men and it must have some significance.The question is"What?",and,if this difference exists,are there others?Research shows that present-day women think differently and behave differently from men.Are some of these differences biological and inborn,a result of evolution?We tend to think that is the influence of society that produces these differences.But could we be wrong?Research showed that these two halves of the brain had different functions,and that the corpus callosum enabled them to work together. For most people,the left half is used for word-handling, analytical and logical activities;the right half works on pictures,patterns and forms.We need both halves working together. And the better the connections,the more harmoniously the two halves work.And,according to research findings,women have the better connections.But it isn't all that easy to explain the actual differences between skills of men and women on this basis.In schools throughout the world girls tend to be better than boys at"language subjects" and boys better at maths and physics.If these differences correspond with the differences in the hemispheric trunk line,there is an unalterable distinction between the sexes.We shan't know for a while,partly because we don't know of any precise relationship between abilities in school subjects and the functioning of the two halves of the brain,and we cannot understand how the two halves interact via the corpus callosum.But this striking difference must have some effect and,because the difference is in the parts of the brain involved in intellect,we should be looking for differences in intellectual processing. Biologists are conducting research where psychologists have given up.
[多选题]共用题干 A Very Slow RideThe surface of the earth may seem very stable to you.But you might be amazed if you knew some of the things that are going on under that surface.The earth has an outer shell of rigid pieces called tectonic plates(地壳构造板块).The plates include both ocean floor and dry land.Some have whole continents on top of them. The con-tinents on top of the plates are just going along for a slow ride,moving only about four inches per year. But even this small movement causes three types of big interactions.One type is ocean ridges.These ridges develop in places where two plates are moving away from each other. As the plates separate,hot magma(岩浆)flows up to fill the space. New crust (地壳)builds up on the plate boundaries and causes ocean ridges. These ridges form long moun-tain ranges,which only rise above the ocean surface in a few places.Another type of reaction-trenches-occurs between two plates that are moving toward each other. As the plates meet,one bends downward and plunges underneath the other. This forms deep ocean trenches. The Marianas Trench off Guam in the western Pacific Ocean has a depth of more than 36,000 feet. This is the lowest point on the ocean floor. If the leading edges of the two colli- ding plates carry continents , then the layers of rock in the overriding plate crumple(变皱)and fold .A plate that carried what is now India collided with the southern edge of the plate that carriedEurope and most of Asia. This caused the Himalayas,the world's highest mountains.The third reaction is transform faults(转换断层).These faults occur where two plates that are traveling in opposite directions slide past each other. Severe earthquakes can occur. The SanAndreas Fault in California is a good example of this type of movement.
[多选题]共用题干 Climate Change Poses Major Risks for Unprepared CitiesA new examination of urban policies has been carried out recently by Patricia Romero Lankao. She is a so- ciologist specializing in climate change and_____________(51) development. She warns that many of the world'5 fast-growing urban areas,especially in developing countries,will likely suffer from the_____________(52)of changing climate. Her work also concludes that most cities are failing to_____________(53)emissions of carbon dioxide and other greenhouse gases. These gases are known to affect the atmosphere."Climate change is a deeply local issue and poses profound_____________ (54) to the growing cities of the world,"says Romero Lankao. "But too few cities are developing effective strategies to protect their residents."Cities are_____________(55)sources of greenhouse gases.And urban populations are likely to be among those most severely affected by future climate change.Lankao's findings highlight ways in which city-resi- dents are particularly vulnerable,and suggest policy interventions that could offer immediate and longer-term ____________ (56).The locations and dense construction patterns of cities often place their populations at greater _____________(57)for natural disasters.Potential threats associated with climate include storm surges and pro- longed hot weather. Storm surges can flood coastal areas and prolonged hot weather can heat_____________(58) paved cities more than surrounding areas. The impacts of such natural events can be more_____________(59)in an urban environment. For example,a prolonged heat wave can increase existing levels of air pollution,causing widespread health problems.Poorer neighborhoods that may_____________(60)basic facilities such as drinking water or a dependable network of roads,are especially vulnerable to natural disasters.Many residents in poorer countries live in substandard housing_____________(61)access to reliable drinking water,roads and basic services.Local governments,therefore,should take measures to_____________(62)their residents."Unfortunately, they tend to move towards rhetoric_____________(63)meaningful responses,"Romero Lankao writes,"They don't impose construction standards that could reduce heating and air conditioning_____________(64).They don't em- phasize mass transit and reduce automobile use.In fact,many local governments are taking a hands-off ap- proach."_____________(65),she urges them to change their idle policies and to take strong steps to prevent the harmful effects of climate change on cities. _________(58)
[多选题]共用题干 Plants in DesertOnly special plants can survive the terrible climate of a desert,for these are regions where the annual range of the soil temperature can be over 75℃.Furthermore,during the summer there are few clouds in the sky to protect plants from the sun's ray.Another problem is the fact that there are frequently strong winds that drive small,sharp particles of sand into the plants,tearing and damaging them.The most difficult problem for all forms of plant life,however,is the fact that the entire annual rainfall occurs during a few days or weeks in spring.Grasses and flowers in desert survive from one year to the next by existing through the long,hot,dry season in the form of seeds.These seeds remain inactive unless the right amount of rain falls.If no rain falls,or if insufficient rain falls,they wait until the next year,or even still the next.Another factor that helps these plants to survive is the fact that their life cycles are short.By the time the water from the spring rains disappears-just a few weeks after it falls-such plants no longer need any.The perennials(多年生植物)have special features that enable them to survive as plants for several years.Thus,nearly all desert perennials have extensive root systems below ground and a small shoot system above ground.The large root network enables the plant to absorb as much water as possible in short time.The small shoot system,on the other hand,considerably limits water loss by evaporation(蒸发).Another feature of many perennials is that after the rainy season they lose their leaves in preparation for the long,dry season,just as trees in wetter climates lose theirs in preparation for the winter.This reduces their water loss by evaporation during the dry season.Then,in next rainy season,they come fully alive once more,and grow new branches,leaves and flowers,just as the grasses and flowers in desert do. The shoot system of perennials can help the plants absorb less of the sun's ray.
[多选题]共用题干 So Many"Earths"The Milky Way(银河)contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate(推算) to the rest of the stars that the telescope could not see.The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life. The Kepler space telescope has been in service for 15 years.
[多选题]共用题干 Less Is MoreIt sounds all wrong—drilling holes in a piece of wood to make it more resistant to knocks. But it works because the energy from the blow gets distributed throughout the wood rather than fo-cusing on one weak spot. The discovery should lead to more effective and lighter packaging mate-rials.Carpenters have known______(51)centuries that some woods are tougher than others. Hickory,for example,was turned into axe handles and cartwheel spokes because it can absorb shocks without breaking. White oak,for example,is much more easily damaued,________(52)it is almost as dense.Julian Vincent at Bathe University and his team were convinced the wood's internal structure could explain the differences.Many trees have tubular vessels that run_______(53)the trunk and carry water to the leav- es .In oak they are large,and arranged in narrow bands,but in hickory they are smaller,and more evenly distributed.The researchers________(54)this layout might distribute a blow's en-ergy throughout the wood, soaking up a bigger hit.To test the idea,they drilled holes 0.65 millimetres across into a block of spruce,a wood with_______(55)vessels,and found that_______(56)withstood a harder knock_______(57)when there were more than about 30 holes per square centimeter did the wood's performance drop off.A uniform substance doesn't cope well with knocks because only a small proportion of the material is actually______( 58).All the energy from the blow goes towards breaking the material in one or two places , but often the pieces left _________( 59 ) are pristine(未经破坏的).But instead of the energy being concentrated in one place,the holes provide many weak spots that all absorb energy as they break,says Vincent.“You are controlling the places______(60) the wood breaks,and it can then absorb more______(61),more safely.”The researchers believe the principle could be applied to any material—_________(62)example,to manufacture lighter and more protective packaging.It could_______(63)be used in car bumpers,crash barriers and armor for military vehicles,says Ulrike Wegst,_______(64) the Max Plank Institute for Mental Research in Stuttgart. But she emphasizes that you'd ________(65)to design the substance with the direction of force in mind.“The direction of loading is crucial,”she says. 58._________
[多选题]共用题干 The iPad1 The iPad is a tablet computer(平板电脑)designed and developed by Apple. It is particularly mar- keted as a platform for audio and visual media such as books , periodicals(期刊), movies , music , and games, as well as web content. At about 1.5 pounds(680 grams),its size and weight are between those of most con- temporary smartphones and laptop computers.Apple released the iPad in April 2010,and sold 3 million of the devices in 80 days.2 The iPad runs the same operating system as iPod Touch and iPhone.It can run its own applications as well as ones developed for iPhone.Without modification,it will only run programs approved by Apple and distributed via its online store.3 Like iPhone and iPod Touch,the iPad is controlled by a multitouch display一a break from most pre- vious tablet computers , which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connec-tion to browse(浏览)the Internet , load and stream media, and install software. Some models also have a 3 G wireless data connection which can connect to GSM 3 G data networks.The device is managed and synchro- nized(同步)by iTunes on a personal computer via USB cable.4 An iPad has different features and applications one can use to execute different and interesting things.There are lots of iPad applications that the owner can use to enhance the way they communicate.Some of these are how to use social networking sites and other online options.One of the most common uses is for e-mail services.iPad applications like Markdown Mail allow the adoption of specific and particular options. They enable the owner to personalize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business users.Some com- panies are adopting iPads in their business offices by distributing or making available iPads to employees. Examples of uses in the workplace include lawyers responding to clients,medical professionals accessing health records during patient exams,and managers approving employee requests.A survey by Frost&Sulli-van shows that iPad usage in workplaces is linked to the goals of increased employee productivity,reduced paperwork,and increased revenue. The iPad will only run programs approved by Apple if not______________.
[多选题]共用题干 Less Is MoreIt sounds all wrong—drilling holes in a piece of wood to make it more resistant to knocks. But it works because the energy from the blow gets distributed throughout the wood rather than fo-cusing on one weak spot. The discovery should lead to more effective and lighter packaging mate-rials.Carpenters have known______(51)centuries that some woods are tougher than others. Hickory,for example,was turned into axe handles and cartwheel spokes because it can absorb shocks without breaking. White oak,for example,is much more easily damaued,________(52)it is almost as dense.Julian Vincent at Bathe University and his team were convinced the wood's internal structure could explain the differences.Many trees have tubular vessels that run_______(53)the trunk and carry water to the leav- es .In oak they are large,and arranged in narrow bands,but in hickory they are smaller,and more evenly distributed.The researchers________(54)this layout might distribute a blow's en-ergy throughout the wood, soaking up a bigger hit.To test the idea,they drilled holes 0.65 millimetres across into a block of spruce,a wood with_______(55)vessels,and found that_______(56)withstood a harder knock_______(57)when there were more than about 30 holes per square centimeter did the wood's performance drop off.A uniform substance doesn't cope well with knocks because only a small proportion of the material is actually______( 58).All the energy from the blow goes towards breaking the material in one or two places , but often the pieces left _________( 59 ) are pristine(未经破坏的).But instead of the energy being concentrated in one place,the holes provide many weak spots that all absorb energy as they break,says Vincent.“You are controlling the places______(60) the wood breaks,and it can then absorb more______(61),more safely.”The researchers believe the principle could be applied to any material—_________(62)example,to manufacture lighter and more protective packaging.It could_______(63)be used in car bumpers,crash barriers and armor for military vehicles,says Ulrike Wegst,_______(64) the Max Plank Institute for Mental Research in Stuttgart. But she emphasizes that you'd ________(65)to design the substance with the direction of force in mind.“The direction of loading is crucial,”she says. 56._________
[多选题]共用题干 The iPad1 The iPad is a tablet computer(平板电脑)designed and developed by Apple. It is particularly mar- keted as a platform for audio and visual media such as books , periodicals(期刊), movies , music , and games, as well as web content. At about 1.5 pounds(680 grams),its size and weight are between those of most con- temporary smartphones and laptop computers.Apple released the iPad in April 2010,and sold 3 million of the devices in 80 days.2 The iPad runs the same operating system as iPod Touch and iPhone.It can run its own applications as well as ones developed for iPhone.Without modification,it will only run programs approved by Apple and distributed via its online store.3 Like iPhone and iPod Touch,the iPad is controlled by a multitouch display一a break from most pre- vious tablet computers , which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connec-tion to browse(浏览)the Internet , load and stream media, and install software. Some models also have a 3 G wireless data connection which can connect to GSM 3 G data networks.The device is managed and synchro- nized(同步)by iTunes on a personal computer via USB cable.4 An iPad has different features and applications one can use to execute different and interesting things.There are lots of iPad applications that the owner can use to enhance the way they communicate.Some of these are how to use social networking sites and other online options.One of the most common uses is for e-mail services.iPad applications like Markdown Mail allow the adoption of specific and particular options. They enable the owner to personalize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business users.Some com- panies are adopting iPads in their business offices by distributing or making available iPads to employees. Examples of uses in the workplace include lawyers responding to clients,medical professionals accessing health records during patient exams,and managers approving employee requests.A survey by Frost&Sulli-van shows that iPad usage in workplaces is linked to the goals of increased employee productivity,reduced paperwork,and increased revenue. Paragraph 4 ______________
[多选题]共用题干 Wide World of RobotsEngineers who build and program robots have fascinating jobs. These researchers tinker(修补)with ma- chines in the lab and write computer software to control these devices."They're the best toys out there," says Howie Choset at Carnegie Mellon University in Pittsburgh.Choset is a roboticist,a person who designs, builds or programs robots.When Choset was a kid,he was interested in anything that moved-cars,trains,animals.He put motors on Tinkertoy cars to make them move.Later,in high school,he built mobile robots similar to small cars.Hoping to continue working on robots,he studied computer science in college.But when he got to graduate school at the California Institute of Technology in Pasadena,Choset's labmates were working on something even cooler than remotely controlled cars:robotic snakes.Some robots can move only forward, backward , left and right. But snakes can twist(扭曲)in many directions and travel over a lot of different types of terrain(地形)."Snakes are far more interesting than the cars,"Choset concluded.After he started working at Carnegie Mellon,Choset and his colleagues there began developing their own snake robots.Choset'5 team programnied robots to perform the same movements as real snakes,such as sliding and inching forward.The robots also moved in ways that snakes usually don't,such as rolling.Choset's snake robots could crawl(爬行)through the grass ,swim in a pond and even climb a flagpole.But Choset wondered if his snakes might be useful for medicine as well. For some heart surgeries,the doctor has to open a patient' s chest ,cutting through the breastbone. Recovering from these surgeries can be very painful. What if the doctor could perform the operation by instead making a small hole in the body and sending in a thin robotic snake?Choset teamed up with Marco Zenati,a heart surgeon now at Harvard Medical School ,to investigate the idea. Zenati practiced using the robot on a plastic model of the chest and they tested the robot in pigs.A company called Medrobotics in Boston is now adapting the technology for surgeries on people.Even after 15 years of working with his team's creations,"I still don't get bored of watching the motionof my robots,"Choset says. Snake robots could move in only four directions.
[多选题]共用题干 Learning DisabilitiesLearning disabilities are very common.They affect perhaps 1 0 percent of all children.Four times as many boys as girls have learning disabilities.Since about 1970,new research has helped brain scientists understand these problems better.Scientists now know there are many different kinds of learning disabilities and that they are caused by many different things.There is no longer any question that all learning disabilities result from differences in the way the brain is organized.You cannot look at a child and tell if he or she has a learning disability.There is no outward sign of the disorder.So some researchers began looking at the brain itself to learn what might be wrong.In one study,researchers examined the brain of a learning-disabled person who had died in an accident. They found two unusual things.One involved cells in the left side of the brain,which control language.These cells normally are white.In the learning disabled person,however,these cells were gray.The researchers also found that many of the nerve cells were not in a line the way they should have been.The nerve cells were mixed together.The study was carried out under the guidance of Norman Geschwind,an early expert on learning disabilities, Doctor Geschwind proposed that learning disabilities resulted mainly from problems in the left side of the brain. He believed this side of the brain failed to develop normally.Probably,he said,nerve cells there did not connect as they should.So the brain was like an electrical device in which the wires were crossed.Other researchers did not examine brain tissue.Instead,they measured the brain's electrical activity and made a map of the electrical signals.Frank Dully experimented with this technique at Children's Hospital Medical Center in Boston.Doctor Dully found large differences in the brain activity of normal children and those with reading problems.The differences appeared throughout the brain.Doctor Dully said his research is evidence that disabilities involve damage to a wide area of the brain,not just the left side.
[多选题]共用题干 So Many"Earths"The Milky Way(银河)contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate(推算) to the rest of the stars that the telescope could not see.The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life. This is the first research finding about the planets with a chance for life.
[多选题]共用题干 Science Fiction1 Amongst the most popular books being written today are those which are usually classified as science fiction.Hundreds of titles are published every year and are read by all kinds of people.Furthermore,some of the most successful films of recent years have been based on science fiction stories.2 It is often thought that science fiction is a fairly new development in literature,but its ancestors can be found in books written hundreds of years ago.These books were often concerned with the presentation of some form of ideal society,a theme which is still often found in modern stories.3 Most of the classics of science fiction,however,have been written within the last hundred years. Books by writers such as Jules Verne and H.G.Wells,to mention just two well-known authors,have been translated into many languages.4 Modern science fiction writers don ' t write about men from Mars(火星)or space adventure stories. They are more interested in predicting the results of technical developments on society and the human mind; or in imagining future worlds which are a reflection of the world which we live in now.Because of this,their writing has obvious political undertones(含义).5 In an age where science fact frequently overtakes(超过)science fiction , the writers may find it difficult to keep ahead of scientific advances.Those who are sufficiently clear-sighted to see the way we are going,however,may provide a valuable lesson on how to deal with the problems which society will inevitably face as it tries to master its new technology. Books written by Jules Verne are______.
[多选题]共用题干 第三篇Internet Helps Families Stay More in TouchMuch has been said about how anti-social the Internet and mobile phones are.The truth is however,according to new research,communication technology is bringing people closer together. A study by the Pew Internet and American Life Project found family members were keeping in regular contact today more than ever before. And this is all down to e-mail,chat,our cellphones and SMS messaging. It makes sense.Years ago,it took a long time to write a letter,then find an envelope and go to the post office to buy a stamp and post it.Today we write mails while we wait for our change in the convenience store and they're sent in an instant.Having free Internet telephone calls also helps us to stay in touch more often and for longer. Everyone's using it,from five-year-olds to tech-savvy grandparents.According to the Pew survey,technology has a very positive effect on communication within families.Researchers asked 2,252 adults whether new technologies had increased the quality of communication with their family. Fifty-three percent said it increased communication with family members they did not live with,two percent said technology decreased this.Numbers were similar for those living in the same house as their family.The project director Lee Rainey said:"There's a new kind of connectedness being built inside of families with these technologies."Survey co-author Barry Wellman agreed:"It used to be that husbands went off to work,wives went off to a different job or else stayed home…and the kids went off to school…and not until 5:30 or 6 o'clock did they ever connect,"he said. Which of the following is not communication technology?
[多选题]共用题干 Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive.volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava(熔岩)that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian(二叠纪)extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 1 0 gigatonnes(十亿吨)of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera(种类)at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid(小行星).He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical InstitUte in France,says that Wignall's idea is provoca- tive.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions. Which of the following is wrong according to Paragraph 3?
[多选题]共用题干 The Tough Grass That Sweetens Our LivesSugar cane was once a wild grass that grew in New Guinea and was used by local people for roofing their houses and fencing their gardens. Gradually a different variety evolved which contained sucrose(蔗糖)and was chewed on for its sweet taste. Over time,sugar cane became a highly valuable commercial plant,grownthroughout the world. _________(46)Sugar became a vital ingredient in all kinds of things ,from confectionery(糖果点心)to medicine , and, as the demand for sugar grew ,the industry became larger and more profitable.__________(47)Many crops withered(枯萎)and died,despite growers' attempts to save them ,and there were fears that the health of the plant would continue to deteriorate.In the 1960s ,scientists working in Barbados looked for ways to make the commercial species stronger and more able to resist disease. They experimented with breeding programmes,mixing genes from the wild species of sugar cane,which tends to be tougher, with genes from the more delicate,commercial type. ___________(48)This sugar cane is not yet ready to be sold commercially,but when this happens,it is expected to he incredibly profitable for the industry.____________ (49)Brazil , which produces one quarter of the world's sugar, has coordinated an intema- tional project under Professor Paulo Arrudo of the Universidade Estaudual de Campinas in Sao Paulo. Teams of experts have worked with him to discover more about which parts of the genetic structure of the plant are important for the production of sugar and its overall health.Despite all the research ,however, we still do not fully understand how the genes function in sugar cane.___________(50)This gene is particularly exciting because it makes the plant resistant to rust,a disease which probably originated in India,but is now capable of infecting sugar cane across the world.Scientists believe they will eventually be able to grow a plant which cannot be destroyed by rust. ________(49)
[多选题]共用题干 Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive.volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava(熔岩)that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian(二叠纪)extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 1 0 gigatonnes(十亿吨)of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera(种类)at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid(小行星).He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical InstitUte in France,says that Wignall's idea is provoca- tive.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions. Permian extinction occurred______.
[多选题]共用题干 第二篇Bullying at school can have serious and harmful negative effects.Because it causes such a problem for many schools,it is important that schools take the appropriate action to minimize its harmful effects.One of the most influential steps that a school can take against bullying is to research and develop a firm understanding of the specific types of bullying the students at the school are facing. Administrators should conduct monthly surveys that ask students about their experiences with bullying, such as whether they were bullied in the past month,whether they witnessed bullying and issues that they think the school administrators should have known about. Administrators should also survey the school's teachers to find out what they know about bullying.Another step that a school administration can take to prevent bullying is to train its teachers, administrators and students' parents about bullying. Hold seminars in your school district to teach parents about ways to communicate with their children if they are bullied at school.Conduct workshops with professional speakers or psychology experts about recognizing the signs of bullying in the classroom for teachers and administrators in your school district.Create newsletters for parents about detail strategies your school is taking to combat bullying or discuss new research on bullying in schools.Last but not least school administrators,teachers and school board members should work together to create a disciplinary plan to use when situations of bullying arise.Make teachers work together in groups to discuss the strategies that they use for dealing with bullying in their individual classrooms.Developing a plan when bullying arises is important in helping students realize that they will face consequences if they choose to bully their peers.Having a disciplinary system in place can help prevent bullying before it even begins. Why is the disciplinary plan important when bullying arises?
[多选题]共用题干 Messages from the Media1. The weather forecast,a story about the candidates in an election,and movie reviews are exam-ples of messages from the media. A communication medium , of which the plural(复数的)form ismedia,is a means of communicating a message .Examples of media are television,radio,news-pa-pers and books and the telephone.The media that can reach many people at once are called mass media.2. It is not difficult to think of other messages we receive through the mass media.Every day we get hundreds of them.Think about advertisements,for example.We see and hear these messages almost everywhere we go .Advertisements are important messages,even though they are sometimes annoying .They help us compare and evaluate products.3. Most of us get more information from the media than from the classroom.Think for a moment, about how you learn about local news and events.Do you depend on other people or the media?What about international news?What is the most important source of information for you?People who are asked this question usually answer,"Television".4. Think of all the messages you received today.Perhaps you read a newspaper during breakfast, or maybe you read advertisements on billboards(露天广告牌)on your way to school. Did you u1sten to a weather forecast or the sports news on the radio this morning?Right now you are getting information through a very important medium of mass communication a book.5. We use the information we get from radio,television,newspapers,and other media to make decisions and form opinions.That is why the mass media are so important.Editorials and articles in newspapers help us decide how to vote,consumer reports on television help us decide how to spend our money,and international news on the radio makes us think and form opinions about question of war and peace. For most people television is the most important______.
[多选题]共用题干 The Biology of MusicHumans use music as a powerful way to communicate.It may also play an important role in love.But what is music,and how does it work its magic?Science does not yet have all the answers.What are two things that make humans different from animals?One is language,and the other is music. It is true that some animals.can sing(and many birds sing better than a lot of people).However,the songs of animals,such as birds and whales,are very limited.It is also true that humans,not animals,have developed musical instruments.Music is strange stuff.It is clearly different from language.However,people can use.music to communicate things-especially their emotions.When music is combined with speech in a song,it is a very powerfnl form of communication.But,biologically speaking,what is music?If music is truly different from speech,then we should process music and language in different parts of the brain.The scientific evidence suggests that this is true.Sometimes people who suffer brain damage lose their ability to process language.However,they don't automatically(自动地)lose their musical abilities.For example , Vissarion Shebalin , a Russian composer , had a stroke(中风)in 1953.It injured the left side of his brain.He could no longer speak or understand speech.He could,however,still compose music until his death ten years later.On the other hand,sometimes strokes cause people to lose their musical ability,but they can still speak and understand speech.This shows that the brain processes music and language separately.By studying the physical effects of music on the body,scientists have also learned a lot about how music influences the emotions.But why does music have such a strong effect on us?That is a harder question to answer.Geoffrey Miller,a researcher at University College,London,thinks that music and love have a strong connection.Music requires -special talent,practice,and physical ability.That's why it may be a way of showing your fitness to be someone's mate.For example,singing in tune or playing a musical instrument requires fine muscular control.You also need a good memory to remmher the notes(音符).And playing or singing those notes correctly suggests that your hearing is in excellent condition.Finally,when a man sings to the woman he loves(or vice versa),it may be a way of showing off.However,Miller's theory still doesn't explain why certain combinations of sounds influence our emotions so deeply.For scientists,this is clearly an area that needs fuither research. The author doesn't suggest that______.
[多选题]共用题干 第三篇On the Trail of the Honey BadgerOn a recent field trip to the Kalahari Desert,a team of researchers learnt a lot more about honey badgers(獾).The team employed a local wildlife expert,Kitso Khama,t& help them locate and follow the badgers across the desert.Their main aim was to study the badgers'movements and behaviour as discreetly (谨慎地)as possible,without frightening them away or causing them to change their natural behaviour. Theyalso planned to trap a few and study them close up before releasing them.In view of the animal's reputation, this was something that even Khama was reluctant to do. "The problem with honey badgers is that they are naturally curious animals, especially when they see something new,"he says. "That, combined with their unpredictable nature,can be a dangerous mixture. If they sense you have food ,for example , they won't be shy about coming right up to you for something to eat. They're actually quite sociable creatures around humans ,but as soon as ther feel they might be in danger, they can become extremely vicious(凶恶的).Fortunately this is rare ,but it does happen."The research confirmed many things that were already known.As expected , honey badgers ate any crea- tures they could catch and kill. Even poisonous snakes , feared and avoided by most other animals,were not safe from them. The researchers were surprised , however, by the animal' s fondness for local melons , probably because of their high water content. Previously researchers thought that the animal got all of its liquid require- ments from its prey(猎物).The team also learnt that , contraryto previous research findings, the badgers oc- casionauy formed loose famiiy groups. They were also able to confirm certain results Irom previous research,including the fact that female badgers never socialised with each other.Following some of the male badgers was a challenge,since they can cover large distances in a short space of time. Some hunting territories cover more than 500 square kilometers. Although they seem happy to share these territories with other males,there are occasional fights over an important food source, and male badgers can be as aggressive towards each other as they are towards other species.As the badgers became accustomed to the presence of people , it gave the team the chance to get up close to them without being the subject of the animals'curiosity-or their sudden aggression. The badgers'eating patterns, which had been disrupted,returned to normal. It also allowed the team to observe more closely some of the other creatures that form working associations with the honey badger, as these seemed to adopt the badgers' relaxed attitude when near humans. Why did the wildlife experts visit the Kalahari Desert?
[多选题]共用题干 ADHD Linked to Air PollutantsChildren have an increased of attention problems,seen as early as grade school,if their no-ses inhaled(吸入)a certain type of air pollution when they were pregnant. That's the finding of a new study.Released when things aren't burned completely,this pollution is known as polycyclic aromatic hydrocarbons,or PAHs.The biggest sources of these PAHs:the burning of fossil fuels, wood and trash.Frederica Perera works at Columbia University's Mailman School of Public Health in New York City.She researches how exposure to things in the environment affects children's health.In a new study,she and her team studied the exposure to air pollution of 233 nonsmoking pregnant women in New York City. Because burning tobacco can spew(排放)PAHs into the air and lungs, Perera's team focused on nonsmokers. The researchers wanted to probe(探查)other sources of PAHs,ones that's would have been hard for an individual to avoid.The team started by testing the blood of each woman during pregnancy.The reason:Any PAHs in a woman's blood would also be available to the baby in her womb.Nine years later,the researchers investigated signs of attention problems in those children,now age 9 .They asked each child's mother a series of questions.These included whatever her child had problems doing things that needed sustained(长期的)mental effort, such as homework or games with friends. The sci-entists also asked if the kids had trouble following instructions or made frequent,careless mis-takes .All of these can be symptoms of a disorder called Attention Deficit Hyperactivity Disorder, or ADHD.About one in U.S.children has ADHD.Among the women studied,traffic and home heating were the primary sources of air pollution exposure,Perera and her team suspect. Some of these women had low levels of PAHs in their blood .Others had high levels.Those with high levels were five times as likely to have children who showed attention problems by age 9 .The new findings were published November 5 in the journal PLOS ONE. Nonsmoking mothers were selected because the effect of smoking on PAHs was unclear.
[多选题]共用题干 1.Certainly no creature in the sea is odder than the common sea cucumber. All living creatures,especially human beings,have their peculiarities,but everything about the little sea cucumber seems unusual.What else can be said about a bizarre animal that,among other eccentricities, eats mud,feeds almost continuously day and night but can live without eating for long periods,and can be poisonous but is considered supremely edible by gourmets?2.For some fifty million years,despite all its eccentricities,the sea cucumber has subsisted on its diet of mud.It is adaptable enough to live attached to rocks by its tube feet,under rocks in shallow water,or on the surface of mud flats.Common in cool water on both Atlantic and Pacific shores, it has the ability to suck up mud or sand and digest whatever nutrients are present.3.Sea cucumbers come in a variety of colors,ranging from black to reddish brown to sand color and nearly white.One form even has vivid purple tentacles.Usually the creatures are cucumber shaped一hence their name一and because they are typically rock inhabitants,this shape,combined with flexibility,enables them to squeeze into crevices where they are safe from predators and ocean currents.4.Although they have voracious appetites,eating day and night,sea cucumbers have the capacity to become quiescent and live at a low metabolic rate feeding sparingly or not at all for long periods,so that the marine organisms that provide their food have a chance to multiply.If it were not for this faculty,they would devour all the food available in a short time and would probably starve themselves out of existence.5.But the most spectacular thing about the sea cucumber is the way it defends itself. Its major enemies are fish and crabs,when attacked,it squirts all its internal organs into water. It also casts off attached structures such as tentacles.The sea cucumber will eviscerate and regenerate itself if it is attacked or even touched;it will do the same if the surrounding water temperature is too high or if the water becomes too polluted. Paragraph 5______
[多选题]共用题干 第一篇Human EvolutionBeing a man has always been dangerous.There are about 105 males born for every 100 females, but this ratio drops to near balance at the age of maturity,and among 70-year-old there are twice as many women as men. But the great universal of male mortality is being changed.Now,boy babies survive almost as well as girls do. This means that,for the first time,there will be an excess of boys in those crucial years when they are searching for a mate. More important,another chance for natural selection has been removed. Fifty years ago,the chance of a baby(particularly a boy baby)surviving depended on its weight. A kilogram too light or too heavy meant almost certain death.Today it makes almost no difference.Since much of the variation is due to genes,one more agent of evolution has gone.There is another way to commit evolutionary suicide:stay alive,but have fewer children.Few people are as fertile as in the past. Except in some religious communities,very few women have 15 children.Nowadays the number of births,like the age of death,has become average.Most of us have roughly the same number of offspring. Again,differences between people and the opportunity for natural selection to take advantage of it have diminished.India shows what is happening. The country offers wealth for a few in the great cities and poverty for the remaining tribal peoples.The grand mediocrity of today一everyone being the same in survival and number of offspring means that natural selection has lost 80%of its power in upper-middle一class India compared to the tribes.For us,this means that evolution is over;the biological Utopia has arrived.Strangely,it has involved little physical change.No other species fills so many places in nature.But in the past 100,000 years一even the past 100 years一our lives have been transformed but our bodies have not. We did not evolve,because machines and society did it for us.Darwin had a phrase to describe those ignorant of evolution:"they look at an organic being as savage looks at a ship,as at something wholly beyond his comprehension."No doubt we will remember a 20th century way of life beyond comprehension for its ugliness. But however amazed our descendants may be at how far from Utopia we were,they will look just like us. The author argues that our bodies have stopped evolving because______.
[多选题]共用题干 Media and Current EventsThe media can impact current events.As a graduate student at Berkeley in the 1960s,I remember experiencing the events related to the People's Park that were occurnng on campus.Some of these events were given national media coverage in the press and on TV.I found it interesting to compare my impressions of what was going on with perceptions obtained from the news media.I could begin to see events of that time feed on news coverage.This also provided me with some healthy insights into the distinctions between these realities.Electronic media are having a greater impact on the people's lives every day.People gather more and more of their impressions from representations.Television and telephone communications are linking people to a global village,or what one writer calls the electronic city.Consider the information that television brings into your home every day.Consider also the contact you have with others simply by using telephone.These media extend your consciousness and your contact.For example,the video coverage of the 1989 San Francisco earth- quake focused on"live action"such as the fires or the rescue efforts.This gave the viewer the impression of total disaster.Television coverage of the Iraqi War also developed an immediacy.CNN reported events as they happened.This coverage was distributed worldwide.Although most people were far away from these events, they developed some perception of these realities.In 1992,many people watched in horror as riots broke out on a sad Wednesday evening in Los Angeles, seemingly fed by video coverage from helicopters.This event was triggered by the verdict(裁定)in the Rodney King beating.We are now in an age where the public can have access to information that enables it to make its own judgments,and most people,who had seen the video of this beating,could not understand how the jury(陪审团)was able to acquit(宣布无罪)the policemen involved.Media coverage of events as they occur also provides powerful feedback that influences events.This can have harmful results,as it seemed on that Wednesday night in Los Angeles.By Friday night the public got to see Rodney King on television pleading,"Can we all get along?"By Saturday,television seemed to provide positive feedback as the Los Angeles riot turned out into a rally for peace.The television showed thousands of people marching with banners and cleaning tools.Because of that,many more people turned out to join the peaceful event they saw unfolding(展开)on television.The real healing , of course , will take much longer , but electronic media will continue to be a part of that process. It can be inferred from the passage that______.
[多选题]共用题干 I'll Be BachComposer David Cope is the inventor of a computer program that writes original works of clas-sical music .It took Cope 30 years to develop the software.Now most people can't_____(51) the difference between music by the famous German composer J. S.Bach(1685-1750)and the Bach-like compositions from Cope's computer.It all started in 1980 in the United States,when Cope was trying to write an opera. He was having____(52)thinking of new melodies,so he wrote a computer program to create the melodies.At first this music was not_____(53)to listen to. What did Cope do?He began to rethink how human beings compose music .He realized that composers,brains_____(54)like big databases. First,they take in all the music that they have ever heard.Then they take_____(55)the music that they dislike.Finally,they make new music from what is_______(56).According to Cope,only the great composers are able to create the database accurately, remember it,and form new musical patterns from it.Cope built a_____(57)database of existing music.He began with hundreds of works by Bach .The software analyzed the data:it______(58)it down into smaller pieces and looked for patterns. It then combined the______(59)into new patterns. Before long,the program could compose short Bach-like works.They weren't good,but it was a start.Cope knew he had more work to do—he had a whole opera to write.He continued to improve the software. Soon it could______(60)more complex music.He also added many other com-posers,including his own work to the database.A few years later,Cope's computer program,called“Emmy”,was ready to help him with his opera. The______(61)required a lot of collaboration between the composer and Emmy. Cope listened to the computer's musical ideas and used the______(62)that he liked.With Emmy,the opera took only two weeks to finish.It was called Cradle Falling,and it was a great _____(63)!Cope received some of the best reviews of his career,but no one knew exactly _____(64)he had composed the work.Since that first opera,Emmy has written thousands of compositions.Cope still gives Emmy feedback on what he likes and doesn't like of her music,_____(65)she is doing most of the hard work of composing these days! 63._________
[多选题]共用题干 B1i'k Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space. Scientists have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational(重力的)force, hydrogen ends up putting pressure onto the star' s surface until it suddenly explodes then collapses.2 Black holes come from stars that are made of hydrogen,other gases and a few metals. When these explode it can turn into a stellar-mass ( 恒星质量)black hole , which can only occur if the star is large enough (should be bigger than the sun) for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle. Try to see and compare:if a star that' s ten times the size of the sun endsup being a black hole that' s no longer than 70 kilometers ,then the Earth would become a black hole that' sonly"fraction of an inch! 3 Objects that get sucked in a black hie will always remain there,never to brsak fren. But rememberthat black holes can only gobble up(吞噬)objects within a specific distance to it It' s possible for a largestar near the sun to become a black hole,but the sun will continue to stay in place. Orbits (轨道)do notchange because the newly formed black hole, contains exactly the same amount of mass as when it was a star,only this time its mass is totally contracted that it can end up as on biggeer tnan a state. 4 So far, astronomers have figured out that black holes exist because of Albert Einstenin's theory of relativity. In the end,through numerous studies ,they have discovered that black holes truly exist. Since blackholes trap light and do not give off light,it is nearly impossible to detect black goles via a telescope. Butastronomers continue to study galaxies (银河系),space and the solar system to understand how black holes misht evolve. It is possible that black holes can exist for millions of years,and later contribute to a biggerprocess in galaxies ,which can eventually lead to creation of new entities(实体).Scientists also credit blackholes as helpful in learning how galaxies began to form. Paragraph 2_____________
[多选题]共用题干 第二篇The Book of LifeSo far,scientists have named about 1.8 million living species,and that's just a fraction of what proba- bly exists on Earth.With so many plants,animals,and other creatures covering the planet,it can be toughto figure out what type of spider is moving up your leg or what kind of bird is flying by.A soon-to-be-launched Web site might help. An international team of researchers has announced thecreation of a Web-based Encyclopedia of Life(EoL).The project aims to catalog every species on Earth in asingle,easy-to-use reference guide.To get the encyclopedia started,the creators will use information from scientific databases that alreadyexist.And eventually,in special sections of the site,nonscientists with specialized knowledge will get to join in.Bird-watchers,for example,will be able to input which birds they've seen and where.The technologyfor this kind of tool has only recently become available.As the EoL develops, you might find it useful for school projects.The site will feature special pages forkids who are studying ecosystems(生态系统)in their neighborhoods. To make sure the encyclopedia isaccurate,scientists will review much of the information added to it. People who visit the site will be able tochoose to leave out pages that haven't been reviewed.Another convenient feature of the EoL is that you'll be able to pick the level of detail you see to matchyour interests,age,and current knowledge.If you wanted to learn about bears for a science class report,forexample,you could use the"novice"setting to get basic information about the animals.On the"expert" setting,on the other hand,you could get much more detailed information about the history,literature and exploration of bears.It now takes years for scientists to collect all the data they need to describe and analyze species.Thecreators of the Encyclopedia of Life hope that their new tool will speed that process. The word"novice"in Paragraph 5 could be best replaced by_______________.
[多选题]共用题干 Older Volcanic EruptionsVolcanoes were more destructive in ancient history,not because they were bigger,but because the carbon dioxide they released wiped out life with greater ease.Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions.Not all volcanic eruptions killed off large numbers of animals,but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock.To his surprise,the older the massive.volcanic eruptions were,the more damage they seemed to do.He calculated the"killing efficiency" for these volcanoes by comparing the proportion of life they killed off with the volume of lava(熔岩)that they produced.He found that size for size,older eruptions were at least 10 times as effective at wiping out life as their more recent rivals.The Permian(二叠纪)extinction,for example,which happened 250 million years ago,is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe.Those volcanoes are thought to have pumped out about 1 0 gigatonnes(十亿吨)of carbon as carbon dioxide.The global warming that followed wiped out 80 percent of all marine genera(种类)at the time,and it took 5 million years for the planet to recover.Yet 60 million years ago,there was another huge amount of volcanic activity and global warming but no mass extinction.Some animals did disappear but things returned to normal within ten thousands of years."The most recent ones hardly have an effect at all,"Wignall says.He ignored the extinction which wiped out the dinosaurs 65 million years ago,because many scientists believe it was primarily caused by the impact of an asteroid(小行星).He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2.Vincent Courtillot,director of the Paris Geophysical InstitUte in France,says that Wignall's idea is provoca- tive.But he says it is incredibly hard to do these sorts of calculations.He points out that the killing power of volcanic eruptions depends on how long they lasted.And it is impossible to tell whether the huge blasts lasted for thousands or millions of years.He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced,and that lava volume may not necessarily correspond to carbon dioxide emissions. What is Vincent Courtillot's attitude toward Wignall's idea?
[多选题]共用题干 Plants in DesertOnly special plants can survive the terrible climate of a desert,for these are regions where the annual range of the soil temperature can be over 75℃.Furthermore,during the summer there are few clouds in the sky to protect plants from the sun's ray.Another problem is the fact that there are frequently strong winds that drive small,sharp particles of sand into the plants,tearing and damaging them.The most difficult problem for all forms of plant life,however,is the fact that the entire annual rainfall occurs during a few days or weeks in spring.Grasses and flowers in desert survive from one year to the next by existing through the long,hot,dry season in the form of seeds.These seeds remain inactive unless the right amount of rain falls.If no rain falls,or if insufficient rain falls,they wait until the next year,or even still the next.Another factor that helps these plants to survive is the fact that their life cycles are short.By the time the water from the spring rains disappears-just a few weeks after it falls-such plants no longer need any.The perennials(多年生植物)have special features that enable them to survive as plants for several years.Thus,nearly all desert perennials have extensive root systems below ground and a small shoot system above ground.The large root network enables the plant to absorb as much water as possible in short time.The small shoot system,on the other hand,considerably limits water loss by evaporation(蒸发).Another feature of many perennials is that after the rainy season they lose their leaves in preparation for the long,dry season,just as trees in wetter climates lose theirs in preparation for the winter.This reduces their water loss by evaporation during the dry season.Then,in next rainy season,they come fully alive once more,and grow new branches,leaves and flowers,just as the grasses and flowers in desert do. Ordinary plants are unable to survive in the desert mainly because of the changeable weather.
[多选题]共用题干 Scotland:A Land of WisdomIn the 1740s,the famous French philosopher Voltaire said"We look to Scotland for all our ideas of civilization."That's not a bad advertisement for any country when it comes to attracting people to search for a first-class education.According to the American author Arthur Herman,the Scots invented the modem world it-self. He argues that Scottish thinkers and intellectuals worked out many of the most important ideas on which modern life depends-everything from the scientific method to market economics.Their ideas did not just spread among intellectuals,but to those people in business,government and the sciences who actually shaped the Western world.It all started during the period that historians call the Scottish Enlightenment(启蒙运动), which is usually seen as taking place between the years 1740 and 1800.Before that,philosophy was mainly concerned with religion.For the thinkers of the Scottish Enlightenment,the proper study of humanity was mankind itself.Their reasoning was practical.For the philosopher David Hume,humanity was the right sub-ject for philosophy because we can examine human behavior and so find real evidence of how peo-ple think and feel. And from that we can make judgments about the societies we live in and make concrete suggestions about how they can be improved,for universal benefit.Hume's enquiry into the nature of knowledge laid the foundations for the scientific method- the pursuit of truth through experiment. His friend and fellow resident of Edinburgh,Adam Smith, famously applied the study of mankind to the ways in which mankind does business. Trade,he ar-gued,was a form of information .In pursuing our own interests through trading in markets,we all come to benefit each other.Smith's idea has dominated modern views of economics.It also has wide applications.He was one of the philosophers to point out that nations can become rich,free and powerful throughpeace,trade and invention.Although the Scottish Enlightenment ended a long time ago,the ideas which evolved at that time still underpin(构成……的基础)our theories of human exchange and enquiry. It also exists in Scotland itself in an educational tradition that combines academic excellence with orientation (方向). David Hume was the first philosopher to study mankind.
[多选题]共用题干 The Greatest Mystery of WhalesThe whale is a warm-blooded,air-breathing animal,giving birth to its young alive,sucking them-and, like all mammals,originated on land.There are many______(51)of this.Its front flippers(鳍状肢), used for steering and stability,are traces of feet.Immense strength is______(52)into the great body of the big whales,and in fact most of a whale's body is one gigantic muscle.The blue whale's pulling strength has been estimated______(53) 400 horsepower.One specimen was reported to have towed(拖)a whaling vessel for seven hours at the ______(54)of eight knot(节).An angry whale will______(55).A famous example of this was the fate of Whaler Essex, ______(56)was sunk off the coast of South America early in the last century.More recently,steel ships have______( 57 ) their plates buckled(使弯曲)in the same way.Sperm whales(抹香鲸)were known to seize the old-time whaleboats in their jaws and crush them.The greatest______(58)of whales is their diving ability.The sperm whale dives to the bottom for his______( 59 ) food , the octopus(章鱼).In that search he is known to go as far down as 3 , 200 feet, where the______(60)is 1,400 pounds to a square inch.Doing so he will______(61) underwater as long as one hour.Two special skills are involved in this storing up enough______(62) (all whales are air-breathed)and tolerating thern great change in pressure.Just how he does it scientists have not______(63).It is believed that some of the oxygen is stored in a special ______(64)of blood vessels,rather than just held in the lungs.And it is believed that a special kind of oi1 in his head is some sort of a compensating mechanism that______(65)adjusts the internal pressure of his body.But since you can't bring a live whale into the laboratory for study,no one knows just how these things work. 63._________
[多选题]共用题干 Women's minds work differently from men's.At least,that is what most men are convinced of. Psychologists view the subject either as a matter of frustration or a joke.Now the biologists have moved into this minefield,and some of them have found that there are real differences between the brains of men and women.But being different,they point out hurriedly,is not the same as being better or worse.There is,however,a definite structural variation between the male and female brain.The difference is in a part of the brain that is used in the most complex intellectual processes一the link between the two halves of the brain.The two halves are linked by a trunk line of between 200 and 300 million nerves,the corpus callosum.Scientists have found quite recently that the corpus callosum in women is always larger and probably richer in nerve fibres than it is in men.This is the first time that a structural difference has been found between the brains of women and men and it must have some significance.The question is"What?",and,if this difference exists,are there others?Research shows that present-day women think differently and behave differently from men.Are some of these differences biological and inborn,a result of evolution?We tend to think that is the influence of society that produces these differences.But could we be wrong?Research showed that these two halves of the brain had different functions,and that the corpus callosum enabled them to work together. For most people,the left half is used for word-handling, analytical and logical activities;the right half works on pictures,patterns and forms.We need both halves working together. And the better the connections,the more harmoniously the two halves work.And,according to research findings,women have the better connections.But it isn't all that easy to explain the actual differences between skills of men and women on this basis.In schools throughout the world girls tend to be better than boys at"language subjects" and boys better at maths and physics.If these differences correspond with the differences in the hemispheric trunk line,there is an unalterable distinction between the sexes.We shan't know for a while,partly because we don't know of any precise relationship between abilities in school subjects and the functioning of the two halves of the brain,and we cannot understand how the two halves interact via the corpus callosum.But this striking difference must have some effect and,because the difference is in the parts of the brain involved in intellect,we should be looking for differences in intellectual processing.
[多选题]共用题干 Learn About Noble Gases(惰性气体)1 Have you ever ridden on a balloon?Many tourist spots offer balloon rides in order for people to see the beauty of a place from above.A balloon contains a noble gas called helium(氦).Formerly,balloons con- tamned hydrogen but hydrogen is very flammable and dangerous when uncontrolled.Therefore,people shifted to helium,which is safer. Helium is safe because it has the properties of the noble gases.2 People once believed that noble gases couldn't chemically react at all.For this reason,they were called inert gases(惰性气体).They were also listed under Group 0 in the old periodic table because scien- tists believed that the gases have zero valence(价)electrons in their outer shell.This was later proven to be untrue when some noble gas compounds were discovered.3 The gases are elements,which share similar properties.These properties include being monoatomic, colorless,odorless,being able to conduct electricity,and having low chemical reactivity.Noble gases include helium,neon,argon,krypton,xenon and radon.These are all found in Group 18,in the right most column of the periodic table.If you look at the periodic table,you will notice that these elements are the only ones which do not have a charge. Helium has the lowest molecular(分子的)weight while radon is the heaviest.4 Remember that chemical reactions occur because atoms have valence electrons,which are electrons in their outer shell.When the outer shell is"unfilled"or the required number of electrons is not yet corn- plete,the atom is more reactive.Noble gases have a full outer shell,meaning that they have complete elec- trons in their outer shell.This complete number varies.For instance,the outer shell of helium has 2 valence electrons while the outer shell of xenon has 8 electrons.Nowadays,there remains to be a few noble gases because of the low chemical reactivity of these said gases.5 because of their properties,noble gases have many important applications.They are widely used in medicine and industries. For instance , liquid helium is used for superconducting magnets(磁体).These magnets are very important in physics and medicine.When a doctor suspects that a person's brain has been damaged,he might request for Magnetic Resonance Imaging(MRI).MRI allows the doctor to"see"the brain,without operating on the patient. Paragraph 5 ____________
[多选题]共用题干 Microchip Research Center CreatedA research center has been______(51)in this Far Eastern country to develop advanced microchip production technology.The center,which will start out with about US$14 million,will help the country develop its chip industry without always depending on imported technology.The center will make use of its research skills and______(52)to develop new technology for _______(53)chip plants.The advent of the center will possibly free the country from the_______(54) that it is always buying almost-outdated technologies from other countries,said the country's flagship chipmaker.______(55),chip plants in this country are in a passive situation because many foreign governments don't allow them to______(56)the most advanced technologies,fearing they will be used for______(57) purposes.Moreover,the high licensing fees they have to pay to technology providers are also an important _(58)for their decision of self-reliance.As mainstream chip production technology______(59)from one generation to the next every three to five years,plants with new technology can make more powerful chips at lower costs,while plants with______(60)equipment,which often cost billions of dollars to build,will be______(61)by the maker.More than 10 chip plants are being built,each costing millions of US dollars.The majority of that money goes to overseas equipment______(62)and technology owners-mainly______(63)Japan and Singapore.Should the new center play a major role in improving the situation in the industry,the country admits the US $14 million investment is still rather small.This country is developing______(64)technologies.Most of the investment will be spent on setting_______(65)with technology and intellectual property owners. 62._________
[多选题]共用题干 Underground Coal FiresCoal burning deep underground in China,India and Indonesia is threatening the environment and human life , scientists have warned.These large-scale______(51)blazes(火焰)cause the ground temperature to heat up and kill surrounding vegetation,produce greenhouse gases and can______(52) ignite(点燃)forest fires , a group of scientists told the annual meeting of the American Association for theAdvancement of Science in Denver.The resulting______(53)of poisonous elements like mercury can also pollute local water sources and soils,they warned."Coal fires are a global disaster,"said Associate Professor Glenn Stracher of East Georgia College inSwainsboro,USA.But______(54)few people know about them.Coal can heat up on its own,and eventually catch fire and bum,if there is a continuous oxygen supply.The heat produced is not caused to______(55)and under the right combinations of sunlight and oxygen,can trigger spontaneous(自发的)catching fire and buming.This can occur underground , in coal stockpiles, abandoned mines or even as coal is transported.______(56)fires in China consume up to 200 million tons of coal per year,delegates were told.In______(57),the U.S.economy consumes about one billion tons of coal annually,said Stracher,______(58)analysis of the likely impact of coal fires has been accepted for publication in the International Journal of Coal Ecology.______(59)underway,coal fires can bum for decades,even centuries.In the process,they release large______(60)of greenhouse gases,poisonous fumes and black particles into the atmosphere.The members of the panel discussed the______(61)these fires may be having on global and regional climate change,and agreed that the underground nature of the fires makes them difficult to______(62).Ultimately,the remote sensing and other techniques should allow scientists to______(63)how much carbon dioxide these fires are emitting(释放).One suggested______(64)of containing the fires was presented by Gary Colaizzi,of the engineering firm Goodson,which has developed a heat-resistant grout(灌浆),which is designed to be pumped into the coal fire to______(65)the oxygen supply. _________64
[多选题]共用题干 Brain Drain1.Brain drain is a phenomenon under which"people of a nation move to another nation due to financial benefits and also due to economical reasons,but there are many more reasons behind it". If we think deeply to the topic,we would find that this phenomenon has more disadvantages than advantages.2.This phenomenon has many advantages for receiving countries which will automatically benefit from the skills and talents of immigrated people who were educated and qualified in their home countnes.3.However,developing countries are deeply affected by this phenomenon since they are deprived from millions of their skilled workers, doctors,hardworking Engineers,and billions of man power. Those elites represent the backbone of their economies and once they travel abroad,their economies will not flourish and promote.In fact,there are many reasons behind brain drain.Firstly,the Government is the first responsible for brain drain. The salaries paid by local companies are much less than multinational foreign companies,which pushes millions of intelligent,hardworking Engineers to leave their native countries to look for a better life and opportunities.Secondly,the status and facilities provided by foreign companies are much higher in quality and quantity.Also,some people find it a matter of pride and dignity to work as an employee in foreign countries.4.But we have to mention that brain drain does not only affect developing countries but also has some advantages for them.People living abroad help foreigners to know about their cultures and traditions.Also,they give information about various natural beauties and tourist spots in their home countries,which encourages tourists to visit them. This in turn increases tourist income.Brain drain also helps in increasing their foreign exchanges.5.But at last you would find that brain drain has more disadvantages than advantages on developing or poor countries.So,to stop brain drain,local governments should make people aware of its harmful effects.Also Government should provide opportunities to their elites and should provide them with handsome salary so that they can serve their own mother nation. Paragraph 3______

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