考试试题

[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 3____________
[多选题]共用题干 A Star Is Born1 The VLT (Very Large Telescope) is the world's largest telescope(望远镜)and is taking astronomers(天文学家) further back to the Big Bang than they ever thoughtpossible.Located 2,600 metres up in the Chilean Andes,it has four huge mirrors,each about the size of a London bus.The VLT is so powerful it can spot a burning match 10,000 kilometres away.2 This astonishing power will allow astronomers to see events in space from the birth of stars to the collision(碰撞)of galaxies(星系)on the edge of the cosmos(宇宙).The VLT is giving astronomers their best-ever view of the cosmos.The power of the VLT to see the smallest detail at the furthest distances makes its designers amazed.3 Take the case of Eta Carinae,one of the most explosive stars in the universe.This star produces ultraviolet laser rays(紫外线)and it will destroy itself in a few million years' time. It is five times brighter than the sun and when it explodes it is going to be a sight worth waiting for!4 But it is at distances of millions,even billions,of light years that the VLT really shows its power. The VLT can detect light that set out on its journey before the earth even existed. This gives astronomers their first-ever detailed views of events that took place in the earliest days of the cosmos.5 In other words,the VLT is a kind of a time machine.It takes astronomers back to a time when complete galaxies crashed into each other. The effects of these past collisionscan now be seen by scientists,and astronomers believe the telescope will reveal more about these exciting' events in the years to come.One day,we might be able to say we have traveled back to the beginning of time,and we will have a much clearer picture of how our planet was born. Paragraph 3_________
[多选题]共用题干 When We Are AsleepEveryone dreams,but some people never recall their dreams,or do so very rarely. Other people always wake up with vivid recollections(记忆)of their dreams, though they forget them very quickly.In an average night of eight hours' sleep,an average adult will dream for around one hundred minutes,probably having three to five dreams,each lasting from ten to thirty minutes.Scientists can detect when someone is having a dream by using an instrument which measures the electrical waves in the brain.During dreaming,these waves move more quickly.Breathing and pulse rate also increase,and there are rapid eye movements under the lids,just as though the dreamer were really looking at moving objects.These signs of dreaming have been detected in all mammals(哺乳动物)studied, including dogs, monkeys, cats, and elephants, and also some birds and reptiles(爬行动物).This period of sleep is called the"D"state.Babies experience the"D"state for around 50%of their sleep;the period reduces to around 25%by the age of 10.Dreams take the form of stories,but they may be strange and with incidents not connected,which make little sense.Dreams are seldom without people in them and they are usually about people we know.One estimate says that two-thirds of the"cast"of our dream dramas are friends and relations.Vision seems an essential part of dreams,except for people blind from birth.Sound and touch are senses also often aroused,but smell and taste are not frequently involved.In"normal"dreams,the dreamer may be taking part,or be only an observer. But he or she cannot control what happens in the dream.However,the dreamer does have control over one type of dream.This type of dream is called a "lucid"(清醒的)dream. Not everyone is a lucid dreamer. Some people are occasional lucid dreamers.Others can dream lucidly more or less all the time.In a lucid dream,the dreamer knows that he is dreaming. We rarely smell things in dreams.
[多选题]共用题干 The Forbidden AppleNew York used to be the city that never sleeps. These days it's the city that never smokes,drinks or does anything naughty(at least,not in public).The Big Apple is quickly turning into the Forbidden Apple.If you wanted a glass of wine with your picnic in Central Park,could you have one?No chance. Drinking alcohol in public isn't allowed. If you decided to feed the birds with the last crumbs(碎屑)of your sandwich, you could be arrested. It's illegal. If you went to a bar for a drink and a cigarette,that would be OK,wouldn't it?Er…no.You can't smoke in public in New York City.What's going on?Why is the city that used to be so open-minded becoming like this?The mayor of New York is behind it all. He has brought in a whole lot of new laws to stop citizens from doing what they want,when they want.The press are shocked. Even the New York police have joined the argument. They re- cently spent$100,000 ona“Don't blame the cop”campaign. One New York police officer said,”We raise money for the city by giving people fines for breaking some very stupid laws. It's all about money.”The result is lot of fines for minor offences. Yoav Kashida,and Israeli tourist,fell asleep on the subway. When he woke up,two police officers fined him because he had fallen asleep on two seats(you mustn't use two seats in the subway).Elle and Serge Schroitman were fined for blocking a driveway with their car. It was their own driveway.The angry editor of Vanity Fair magazine,Graydon Carter,says.”Under New York City law it is acceptable to keep a gun in your place of work,but not an empty ashtray.”He should know. The police came to his office and took away his ashtray(烟灰缸).But not all of New York's inhabitants are complaining. Marcia Dugarry,72,said,”The city has changed for the better. If more cities had these laws,America would be a better place to live.”Nixon Patotkis,38,a barman,said,”I like the new laws. If people smoked in here, we'd go home smelling of cigarettes.”Recent figures show that New York now has fewer crimes per 100,000 people than 193 other US cities.And it's true一It's safer,cleaner and more healthy than before. But let'sbe honest一who goes to New York for its clean streets? Eating apples in the park is illegal.
[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 Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive(原始的)man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship(崇拜)a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve(曲线)of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling(闪烁)lights. Some early astronomers(天文学家)believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it. Early astronomers believed that the sky was a crystal shell or series of crystal shells because_________.
[多选题]共用题干 Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles(束)of electromagnetic(电磁)energy called photons(光子).Today,scientists agree that light has a dual(二重)nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference(干扰), etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel(旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum(真空),however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane. Paragraph 3______
[多选题]共用题干 Ecosystem1. The word “ecosystem” is short for ecological(生态的)system. An ecosystem is where living creatures expand within a given area. You can say that an ecosystem is the natural environment where biological organisms(生物)such as plants,animals and humans co-exist in this world. So naturally that includes you and me. Yes,we are all members of an ecosystem!2 .There are different kinds of ecosystems depending on the type of surface or environ-ment. Most are naturally made such as the ocean or lake and the desert or rainforest.Some are man-made or artificial to encourage co-habitation(同居)between living and non-living things in a monitored environment,such as a zoo or garden.3 .Plants make up the biggest group of biological creatures within an ecosystem,and that's because they are the natural food producers for everyone. Plants raised in the earth need air and collect sunlight to help them grow. When they grow,the plants and its fruits or flowers eventually become a source of food to animals,microorganisms(微生物)and even hu- mans,of course. Food is then converted to energy for the rest of us to function,and this hap-pens in a never-ending cycle until the living creatures die and break up back in the earth.4 .Ecosystems are the basis of survival for all living things.We depend on plants and ani-mals for food. In order for us to exist,we need to grow and care about other organisms. We also need to care for the non-living things within our environment like our air and water so we can continue living as a population. Since plants,animals and humans are all of various species(物种),we all play a role in maintaining the ecosystem.5 .To preserve our ecosystems,we should stop using too much energy,which happens when we consume more than our share of resources. Humans should not disturb the natural habitat(栖息地)of plants and animals,and allow them to grow healthily for the cycle to con-tinue. Too many people in a habitat can mean displacement(搬迁): imagine being thrown out of your home because there is no more space for everyone. Worse,overpopulation can also ru- in the environment and cause destruction of existing plants and animals. To protect our ecosystems we should not use more than______.
[多选题]共用题干 Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles(束)of electromagnetic(电磁)energy called photons(光子).Today,scientists agree that light has a dual(二重)nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference(干扰), etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel(旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum(真空),however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane. Paragraph 4______
[多选题]共用题干 Mt. Desert IslandThe coast of the State of Maine is one of the most irregular in the world.A straight line running from the southernmost coastal city to the northernmost coastal city would measure about 225 miles.If you followed the coastline between these points,you would travel more than ten times as far. This irregularity is the result of what is called a drowned coastline._________(46)At that time,the whole area that is now Maine was part of a mountain range that towered above the sea. As the glacier(冰川)descended , however , it expended enormous force on those mountains,and they sank into the sea.As the mountains sank,ocean water charged over the lowest parts of the remaining land,forming a series of twisting inlets and lagoons(咸水湖).The highest parts of the former mountain range , nearest the shore, remained as islands.________(47)Maine fossils found here were 225 feet above sea level,indicating the level of the shoreline prior to the glacier.The 2,500-mile-long rocky coastline of Maine keeps watch over nearly two thousand islands. Many of these islands are tiny and uninhabited,but many are home to thriving communities.Mt. Desert Island is one of the largest,most beautiful of the Maine coast islands.Measuring 16 miles by 12 miles,Mt. Desert was es- sentially formed as two distinct islands._______(48)For years,Mt. Desert Island,particularly its major settlement,Bar Harbor,afforded summer homes for the wealthy.Recently though,Bar Harbor has become a rapidly growing arts community as well.But,the best part of the island is the unspoiled forest land known as Acadia National Park.Because the island sits on the boundary line between the temperate(温带)and sub-Arctic zones,the island supports the plants and ani- mals of both zones as well as beach , inland , and alpine(高山的)plants. _________( 49 ) The establish- ment of Acadia National Park in 1916 means that this natural reserve will be perpetually available to all people,not just the wealthy.Visitors to Acadia may receive nature instruction from the park naturalists as well as enjoy camping,cycling,and boating.Or they may choose to spend time at the archeological museum, learning about the Stone Age inhabitants of the island.The best view on Mt.Desert Island is from the top of Cadillac Mountain._________(50)From thesummit,you can gaze back toward the mainland or out over the Atlantic Ocean and contemplate the beauty created by a retreating glacier. _________(50)
[多选题]共用题干 More Than 8 Hours Sleep Too Much of a Good Thing1 Although the dangers of too little sleep are widely known,new research suggests that people who sleep too much may also suffer the consequences.2 Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep,as well as a number of other sleep problems,than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling re-freshed after a night's sleep than 8-hour sleepers.3 These findings,which DL Daniel Kripke reported in the journal Psychosomatic Medicine,demonstrate that people who want to get a good night's rest may not need to set aside more than 8 hours a night.He added that“it might be a good idea” for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed,but cau-tioned that more research is needed to confirm this.4 Previous studies have shown the potential dangers of chronic shortages of sleep一for instance,one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more.5 For the current report,Kripke reviewed the responses of 1,004 adults to sleep ques-tionaires,in which participants indicated how much they slept during the week and whether they experienced any sleep problems. Sleep problems included waking in the middle of the night,arising early in the morning and being unable to fall back to sleep,and having fatigue interfere with day-to-day functioning.6 Kripke found that people who slept between 9 and 10 hours each night were more like-ly to report experiencing each sleep problem than people who slept 8 hours. In an interview, Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence,he added that one way to help insomnia is to spend less time in bed.“It stands to reason that if a person spends too long a time in bed,then they'll spend a higher percentage of time awake.”he said. Paragraph 2______
[多选题]共用题干 Understanding Autism1 Autism(孤独症)is a life-long developmental disability that prevents individuals from properly understanding what they see,hear and other senses.This results in severe problems of social relationships,communication and behavior. Individuals with autism have to painstakingly(费力地)learn normal patterns of speech and communication, and appropriate ways to relate to people,objects and events,in a similar manner to those who have had a stroke.2 The cause of autism is still unknown.Some research suggests a physical problem affecting those parts of the brain that process language and information coming in from the senses. There may be some imbalance of certain chemicals in the brain. Genetic(遗传的) factors may sometimes be involved.Autism may indeed result from a combination of several "causes".3 Most people with mental retardation(智力迟钝)show relatively even skill development. Individuals with autism,however,typically show uneven skill development,with deficits(欠缺)in certain areas一most frequently in their ability to communicate and relate to others一and distinct skills in other areas.It is important to distinguish autism from mental retardation or other disorders , since diagnostic(诊断的)confusion may lead to inappropriate and ineffective treatment techniques.4 In general,individuals with autism perlorm best at jobs which are structured and involve a degree of repetition.Some people who have autism are working as artists,piano tuners, painters,farm workers,office workers,computer operators,dishwashers,assembly lineworkers,or employees of sheltered workshops or other sheltered work settings. A typical feature of people with autism is their uneven_______.
[多选题]共用题干 Solar Power Without Solar CellsA dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-netic field were so weak that they could be________(53).What Rand and his colleagues found is that at the right intensity,when light is traveling through a material that does not_________(54)electricity,the light field can generate magnetic effects that are 100 million times stronger than previously expected.Under these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect."This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power________(57)."What makes this possible is a previously unde- tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi- tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a battery.Rand and Fisher found that under the right circumstances and in right types of materials,the light's magnetic field can also create optical rectification.The light must be shone through a________(60)that does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that would work at lower intensities,Fisher said."In our most recent paper,we show that incoherent light like sunlight is theoretically almost _________(62)effective in producing charge separation as laser light is,"Fisher said.This new_________(63)could make solar power cheaper,the researchers say.They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's equivalent to today's commercial-grade solar cells."To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for _________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent ceramics might be even better." _________(64)
[多选题]共用题干 Solar Power Without Solar CellsA dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-netic field were so weak that they could be________(53).What Rand and his colleagues found is that at the right intensity,when light is traveling through a material that does not_________(54)electricity,the light field can generate magnetic effects that are 100 million times stronger than previously expected.Under these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect."This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power________(57)."What makes this possible is a previously unde- tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi- tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a battery.Rand and Fisher found that under the right circumstances and in right types of materials,the light's magnetic field can also create optical rectification.The light must be shone through a________(60)that does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that would work at lower intensities,Fisher said."In our most recent paper,we show that incoherent light like sunlight is theoretically almost _________(62)effective in producing charge separation as laser light is,"Fisher said.This new_________(63)could make solar power cheaper,the researchers say.They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's equivalent to today's commercial-grade solar cells."To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for _________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent ceramics might be even better." _________(63)
[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. iPad applications enable the owner's email accounts to be______________.
[多选题]共用题干 The Forbidden AppleNew York used to be the city that never sleeps. These days it's the city that never smokes,drinks or does anything naughty(at least,not in public).The Big Apple is quickly turning into the Forbidden Apple.If you wanted a glass of wine with your picnic in Central Park,could you have one?No chance. Drinking alcohol in public isn't allowed. If you decided to feed the birds with the last crumbs(碎屑)of your sandwich, you could be arrested. It's illegal. If you went to a bar for a drink and a cigarette,that would be OK,wouldn't it?Er…no.You can't smoke in public in New York City.What's going on?Why is the city that used to be so open-minded becoming like this?The mayor of New York is behind it all. He has brought in a whole lot of new laws to stop citizens from doing what they want,when they want.The press are shocked. Even the New York police have joined the argument. They re- cently spent$100,000 ona“Don't blame the cop”campaign. One New York police officer said,”We raise money for the city by giving people fines for breaking some very stupid laws. It's all about money.”The result is lot of fines for minor offences. Yoav Kashida,and Israeli tourist,fell asleep on the subway. When he woke up,two police officers fined him because he had fallen asleep on two seats(you mustn't use two seats in the subway).Elle and Serge Schroitman were fined for blocking a driveway with their car. It was their own driveway.The angry editor of Vanity Fair magazine,Graydon Carter,says.”Under New York City law it is acceptable to keep a gun in your place of work,but not an empty ashtray.”He should know. The police came to his office and took away his ashtray(烟灰缸).But not all of New York's inhabitants are complaining. Marcia Dugarry,72,said,”The city has changed for the better. If more cities had these laws,America would be a better place to live.”Nixon Patotkis,38,a barman,said,”I like the new laws. If people smoked in here, we'd go home smelling of cigarettes.”Recent figures show that New York now has fewer crimes per 100,000 people than 193 other US cities.And it's true一It's safer,cleaner and more healthy than before. But let'sbe honest一who goes to New York for its clean streets? The businessman like the new laws.
[多选题]共用题干 Hurricane1 A hurricane(飓风)is a tropical storm with winds that have reached a constant speed of 74 miles per hour. Hurricane winds blow in a large spiral(螺旋)around a relative calm center know as the“eye”.The“eye” is generally 20 to 30 miles wide,and the storm may ex- tend outward 400 miles. As a hurricane nears land,it can bring heavy rains,high winds,and storms(风暴潮).The storm surges and heavy rains can lead to flooding.2 Hurricanes are given a different label,depending on where they occur. If they begin over the North Atlantic Ocean,the Caribbean Sea,the Gulf of Mexico,or the Northeast Pa-cific Ocean,they are called hurricanes.Similar storms that occur in the Northwest Pacific Ocean west of the International Date Line are called typhoon. Near Australia and in the India Ocean, they are referred to as tropical cyclones(龙卷风).3 When a hurricane hits land,it can do great damage through its fierce winds,heavy rains , inland(内陆的)flooding, and huge waves crashing onto the shore. During a hurri-cane,homes,businesses,and public buildings may be damaged or destroyed;road and bridges can be washed away. A powerful hurricane can kill more people and destroy more property than any other natural disaster. Fishermen are at special risk from hurricanes as they may be at sea when a hurricane arrives and not be able to get to a safe harbour if they do not receive adequate warning.4 If a hurricane is coming in your area,the most important thing is to stay calm and find shelter immediately. Go to your safe room. If you do not have one,stay indoors during the hurricane and go to a safer place near the center of your home. Cover yourself with a blanket and be sure to keep away from windows and glass doors,because if the glass breaks it's real-ly dangerous. Do not be fooled if there is a lull(暂停);it could be the eye of the storm-winds will pick up again. Paragraph 2_________
[多选题]共用题干 第二篇Download Knowledge Directly to Your BrainFor the first time,researchers have been able to hack into the process of learning in the biain,using induced brain patterns to create a learned behavior. It's not quite as advanced as an instant Kung-fu down- load,and it's not as sleek as cognitive inception,but it's still an important finding that could lead to new teaching and rehabilitation techniques.Future therapies could decode the brain activity patterns of an athlete or a musician,and use them as a benchmark for teaching another person a new activity,according to the researchers.Scientists from Boston University and ATR Computational Neuroscience Laboratories in Kyoto used functional magnetic resonance imaging,or fMRI,to study the learning process.They were examining the adult brain's aptitude for visual perceptual learning,or VPL,in which repetitive training improves a per- son's performance on a particular task.Whether adults can do this as well as young people has been an on- going debate in neuroscience.Led by BU neuroscientist Takeo Watanabe,researchers used a method called decoded fMRI neurofeed- back to stimulate the visual cortex.First they showed participants circles at different orientations.Then they used fMRI to watch the participants'brain activity.The researchers were then able to train the participants to recreate this visual cortex activity.The volunteers were again placed in MRI machines and asked to visualize shapes of certain colors.The participants were asked to"somehow regulate activity in the posterior part of the brain"to make a solid green disc as large as they could.They were told they would get a paid bonus proportional to the size of this disc, but they weren't told anything about what the disc meant.The researchers watched the participants'brain activity and monitored the activation patterns in their visual cortices."Participants can be trained to control the overall mean activation of an entire brain region,"the study authors write,"or the adtivation in one region relative to that in another region."This worked even when test subjects were not aware of what they were learning,the researchers said."The most surprising thing in this study is that mere inductions of neural activation patterns corresponding to a specific visual feature led to visual performance improvement on the visual feature,without presenting the fea- ture or subjects' awareness of what was to be learned,"Watanabe said in a statement.Watanabe and colleagues said this method can be a powerful tool."It can'incept' a person to acquire new learning, skills,or memory,or possibly to restore skills or knowledge that has been damaged through accident,disease,or aging,without a person's awareness of what is learned or memorized,"they write. The finding of the study is most significant in that learning_________.
[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. Among the elements of noble gases helium is the____________.
[多选题]共用题干 Solar Power Without Solar CellsA dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-netic field were so weak that they could be________(53).What Rand and his colleagues found is that at the right intensity,when light is traveling through a material that does not_________(54)electricity,the light field can generate magnetic effects that are 100 million times stronger than previously expected.Under these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect."This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power________(57)."What makes this possible is a previously unde- tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi- tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a battery.Rand and Fisher found that under the right circumstances and in right types of materials,the light's magnetic field can also create optical rectification.The light must be shone through a________(60)that does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that would work at lower intensities,Fisher said."In our most recent paper,we show that incoherent light like sunlight is theoretically almost _________(62)effective in producing charge separation as laser light is,"Fisher said.This new_________(63)could make solar power cheaper,the researchers say.They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's equivalent to today's commercial-grade solar cells."To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for _________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent ceramics might be even better." _________(59)
[单选题]Cell Phone Lets Your Secrets Out   Your cell phone holds secrets about you.Besides the names and numbers that you've programmed into it, ______traces____(51) of your DNA linger (遗留) on thedevice according to a new study   DNA is genetic (遗传的)material _____that_____ (52) appears in every cell. Like your fingerprint, yourDNA is _____unique______ (53) to you——unless you have an identical twin. Scientiststoday analyze DNA in blood, saliva (唾液), orhair left ____behind_______ (54) at the scene of a crime. The results oftenhelp detectives identify ____criminals______ (55) and their victims. Your cellphone can reveal more about you ____than_____ (56) you might think.   Meghan J. McFadden, a scientist at McMasterUniversity in Hamilton, Ontario, heard about a crime in which the suspect bledonto a cell phone and later dropped the____device_____ (57). This made herwonder whether traces of DNA lingered on cell phones一evenwhen no blood was___involved_____(58). She and colleague Margaret Wallace ofthe City University of NewYork analyzed the flip-open phones(翻盖手机)of10 volunteers. They used swabs (药签) tocollect _____invisible___ (59) traces of the users from two parts of the phone:the outside, where the user ____holds_____(60) it, and the speaker which isplaced at the user's ear   The scientists cleaned the phones using asolution made mostly__of____(61) alcohol. The aim of washing was to remove alldetectable traces of DNA. The owners got their phones back for another week.Then the researchers ___returned________ (62) the phones and cleaned each phoneonce more.   The scientists discovered DNA that _____belonged______(63) to the phone's speaker on each of the phones. Better samples werecollected from the outside of each phone, but those swabs also picked up DNAthat belonged to other people who had apparently also ____handed______ (64) thephone   Surprisingly, DNA showed up even in swabsthat were taken immediately after the phones were scrubbed. That suggests thatwashing won't remove all traces of ___evidence________ (65) from a criminal'sdevice. So cell phones can now be added to the list of clues that can clinch (确定)a crime-scene investigation. 文章(41~55)   
[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. _________(55)
[多选题]共用题干 Hurricane1 A hurricane(飓风)is a tropical storm with winds that have reached a constant speed of 74 miles per hour. Hurricane winds blow in a large spiral(螺旋)around a relative calm center know as the“eye”.The“eye” is generally 20 to 30 miles wide,and the storm may ex- tend outward 400 miles. As a hurricane nears land,it can bring heavy rains,high winds,and storms(风暴潮).The storm surges and heavy rains can lead to flooding.2 Hurricanes are given a different label,depending on where they occur. If they begin over the North Atlantic Ocean,the Caribbean Sea,the Gulf of Mexico,or the Northeast Pa-cific Ocean,they are called hurricanes.Similar storms that occur in the Northwest Pacific Ocean west of the International Date Line are called typhoon. Near Australia and in the India Ocean, they are referred to as tropical cyclones(龙卷风).3 When a hurricane hits land,it can do great damage through its fierce winds,heavy rains , inland(内陆的)flooding, and huge waves crashing onto the shore. During a hurri-cane,homes,businesses,and public buildings may be damaged or destroyed;road and bridges can be washed away. A powerful hurricane can kill more people and destroy more property than any other natural disaster. Fishermen are at special risk from hurricanes as they may be at sea when a hurricane arrives and not be able to get to a safe harbour if they do not receive adequate warning.4 If a hurricane is coming in your area,the most important thing is to stay calm and find shelter immediately. Go to your safe room. If you do not have one,stay indoors during the hurricane and go to a safer place near the center of your home. Cover yourself with a blanket and be sure to keep away from windows and glass doors,because if the glass breaks it's real-ly dangerous. Do not be fooled if there is a lull(暂停);it could be the eye of the storm-winds will pick up again. A powerful hurricane may become the most destructive________.
[多选题]共用题干 Chimpanzees1 Chimpanzees(黑猩猩)will soon be extinct(灭绝).If the present rate of hunting and habitat(栖息地)destruction continues, then within 20 years, there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy(悲剧).Chimpan-zee extinction may also have profound implications(含意)for the survival of their distant relatives一human beings.2 In 1975 the biologist Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes(基因组)match by over 98%. Compare this to the mouse, used as model for human disease in lab tests,which shares only 60% of its DNA with us.In fact, chimpanzees are far more similar to humans than they are to any other species of monkey. As well as resembling us genetically,chimps are highly intelligent and able to use tools.These facts alone should be enough to make protection of chimps an urgent priority(优先).But there is another,more selfish reason to preserve the chimp.3 The chimpanzees' trump card(王牌)comes in the field of medical research. Chimpan-zees are so similar to humans that veterinarians(兽医)often refer to human medical text-books when treating them. Yet chimpanzees do show differences in several key areas.In parti-cular,chimps are much more resistant to a number of major diseases.It is this ability that is so interesting.4 For example,chimps seem to show a much higher resistance than humans to HIV,the virus that causes AIDS. Indeed,their use as experimental animals in AIDS research has de-clined because they are so resistant.5 By sequencing the chimp genome and pinpointing(找到)the place where the chimpan-zee DNA sequence differs from that of humans,scientists hope to be able to discover which part of the genetic code gives chimps their increased resistance to some diseases. This,they hope,will allow them to develop new and more effective treatments for the human forms of these diseases. Such treatments could include the production of new drugs or even the altera-tion(改变)of the human genetic sequence. The recently completed human genome sequen-cing project has shown that such an effort is now well within our reach. Paragraph 4______.
[多选题]共用题干 Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles(束)of electromagnetic(电磁)energy called photons(光子).Today,scientists agree that light has a dual(二重)nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference(干扰), etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel(旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum(真空),however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane. Paragraph 2______
[多选题]共用题干 Travel Across AfricaFor six hours we shot through the barren(荒芜的)landscape of the Karoo desert inSouth Africa. Just rocks and sand and baking sun. Knowing our journey was ending,Daniel and I just wanted to remember all we had seen and done. He used a camera. I used words. I had already finished three notebooks and was into the fourth,a beautiful leather notebook I'd bought in a market in Mozambique.Southern Africa was full of stories and visions.We were almost drunk on sensations,the roaring(咆哮)of the water at Victoria Falls, the impossible silence of the Okavango Delta in Botswana.And then the other things:dogs in the streets,whole families in Soweto living in one room,a kilometre from clean water.As we drove towards the setting sun,a quietness fell over us. The road was empty一we hadn't seen another car for hours.And as I drove,something caught my eye,something moving close enough to touch them,to smell their hot breath. I didn't know how long they had been there next to us.I shouted to Dan:“Look!”But he was in a deep sleep,his camera lying useless by his feet. They raced the car for a few seconds,then disappeared far behind us,a memory of he- roic forms in the red landscape.When Daniel woke up an hour later I told him what had happened.”Wild horses?”he said.”Why didn't you wake me up,Sophia?””I tried. But they were gone after a few seconds.””Are you sure you didn't dream it?””You were the one who was sleeping!””Typical”,he said.”The best photos are the ones we never take.”We checked into a dusty hotel and slept the sleep of the dead. Daniel and Sophia saw a lot of wonderful things.
[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. _________(54)
[多选题]共用题干 Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles(束)of electromagnetic(电磁)energy called photons(光子).Today,scientists agree that light has a dual(二重)nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference(干扰), etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel(旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum(真空),however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane. Paragraph 4______
[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 par-ticularly marketed 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 contemporary smartphones and laptop comput-ers.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 pro-grams 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 previous tablet computers, which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connection to browse(浏览)the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to GSM 3G data networks. The devices is managed and synchronized(同步)by iTunes on a per-sonal computer via USB cable.4 An iPad has different features and applications one can use to execute different and in-teresting 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 personal-ize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business us-ers. Some companies 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 manag-ers approving employee requests.A survey by Frost Sullivan shows that iPad usage in work-places is linked to the goals of increased employees productivity,reduced paperwork,and in-creased revenue. Paragraph 3______
[多选题]共用题干 Solar Power Without Solar CellsA dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-netic field were so weak that they could be________(53).What Rand and his colleagues found is that at the right intensity,when light is traveling through a material that does not_________(54)electricity,the light field can generate magnetic effects that are 100 million times stronger than previously expected.Under these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect."This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power________(57)."What makes this possible is a previously unde- tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi- tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a battery.Rand and Fisher found that under the right circumstances and in right types of materials,the light's magnetic field can also create optical rectification.The light must be shone through a________(60)that does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that would work at lower intensities,Fisher said."In our most recent paper,we show that incoherent light like sunlight is theoretically almost _________(62)effective in producing charge separation as laser light is,"Fisher said.This new_________(63)could make solar power cheaper,the researchers say.They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's equivalent to today's commercial-grade solar cells."To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for _________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent ceramics might be even better." _________(52)
[多选题]共用题干 Ecosystem1. The word “ecosystem” is short for ecological(生态的)system. An ecosystem is where living creatures expand within a given area. You can say that an ecosystem is the natural environment where biological organisms(生物)such as plants,animals and humans co-exist in this world. So naturally that includes you and me. Yes,we are all members of an ecosystem!2 .There are different kinds of ecosystems depending on the type of surface or environ-ment. Most are naturally made such as the ocean or lake and the desert or rainforest.Some are man-made or artificial to encourage co-habitation(同居)between living and non-living things in a monitored environment,such as a zoo or garden.3 .Plants make up the biggest group of biological creatures within an ecosystem,and that's because they are the natural food producers for everyone. Plants raised in the earth need air and collect sunlight to help them grow. When they grow,the plants and its fruits or flowers eventually become a source of food to animals,microorganisms(微生物)and even hu- mans,of course. Food is then converted to energy for the rest of us to function,and this hap-pens in a never-ending cycle until the living creatures die and break up back in the earth.4 .Ecosystems are the basis of survival for all living things.We depend on plants and ani-mals for food. In order for us to exist,we need to grow and care about other organisms. We also need to care for the non-living things within our environment like our air and water so we can continue living as a population. Since plants,animals and humans are all of various species(物种),we all play a role in maintaining the ecosystem.5 .To preserve our ecosystems,we should stop using too much energy,which happens when we consume more than our share of resources. Humans should not disturb the natural habitat(栖息地)of plants and animals,and allow them to grow healthily for the cycle to con-tinue. Too many people in a habitat can mean displacement(搬迁): imagine being thrown out of your home because there is no more space for everyone. Worse,overpopulation can also ru- in the environment and cause destruction of existing plants and animals. Plants are essential in an ecosystem because to other living creatures they are______.
[多选题]共用题干 A Star Is Born1 The VLT (Very Large Telescope) is the world's largest telescope(望远镜)and is taking astronomers(天文学家) further back to the Big Bang than they ever thoughtpossible.Located 2,600 metres up in the Chilean Andes,it has four huge mirrors,each about the size of a London bus.The VLT is so powerful it can spot a burning match 10,000 kilometres away.2 This astonishing power will allow astronomers to see events in space from the birth of stars to the collision(碰撞)of galaxies(星系)on the edge of the cosmos(宇宙).The VLT is giving astronomers their best-ever view of the cosmos.The power of the VLT to see the smallest detail at the furthest distances makes its designers amazed.3 Take the case of Eta Carinae,one of the most explosive stars in the universe.This star produces ultraviolet laser rays(紫外线)and it will destroy itself in a few million years' time. It is five times brighter than the sun and when it explodes it is going to be a sight worth waiting for!4 But it is at distances of millions,even billions,of light years that the VLT really shows its power. The VLT can detect light that set out on its journey before the earth even existed. This gives astronomers their first-ever detailed views of events that took place in the earliest days of the cosmos.5 In other words,the VLT is a kind of a time machine.It takes astronomers back to a time when complete galaxies crashed into each other. The effects of these past collisionscan now be seen by scientists,and astronomers believe the telescope will reveal more about these exciting' events in the years to come.One day,we might be able to say we have traveled back to the beginning of time,and we will have a much clearer picture of how our planet was born. The VLT will allow scientists to see events_________.
[多选题]共用题干 Motion SicknessLiving in space looks like lots of fun.You can do certain things in space(like floating around,or pushing huge objects)that you cannot do on earth.But being in space can do things to you,too.If you stay too long in a gravity-free environment,your bones could become weak,and a small spaceship just might annoy you after a while,because space travel could make you seasick!On July 4, 1982,after seven days orbiting the earth,astronauts Thomas K. Mattingly and Henry W. Hartsfield returned home.Although not all of the experiments on board worked properly,the flight basically seemed to be a success except for one"little"thing: early in the flight,astronaut Hartsfield became"seasick".Thomas Mattingly,who is also a jet pilot and is highly resistant to motion sickness on earth,did much better.Mattingly sailed through space with a steady stomach.But no one knows why Hartsfield felt uneasy and Mattingly did not.So far it seems there is no reliable way to predict who will become motion sick in outer space and who will not.In all,at least four astronauts have suffered from space motion sickness. Russian and American scientists are working together to try to understand and solve the motion sickness.Space program officials worry that if so many highly-trained pilots get sick in space,what will happen when civilians start flying in the shuttle?Motion sickness is a disagreeable feeling that comes from the pitching,rolling, swaying,or just the moving of the object you are riding in or on.Symptoms of motion sickness include:dizziness,headache,a sinking feeling in the stomach,and vomiting (呕吐).Why does motion make some people ill?Doctors believe that motion sickness is caused by a disturbance in the inner ear.Our ears do more than give us hearing.A part of the ears gives us a sense of balance and helps make us aware of whether we are right side up or upside down.If you know that you get carsick or seasick,what can you do?Speak to your doctor. There are certain medicines available that can help stop that uneasy feeling.But many of them can also make you sleepy.Usually they work best takenbefore you begin feeling ill.Some people also recommend water,ice cubes,mints,or plain toast.But these remedies do not always work for everyone.Perhaps,since motion sickness is such a big problem in outer space,researchers may soon find a way to cure the astronauts一and those of us who stay on earth. Russian and American scientists are working together to solve the problem of motion sickness in astronauts.
[多选题]共用题干 More Than 8 Hours Sleep Too Much of a Good Thing1 Although the dangers of too little sleep are widely known,new research suggests that people who sleep too much may also suffer the consequences.2 Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep,as well as a number of other sleep problems,than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling re-freshed after a night's sleep than 8-hour sleepers.3 These findings,which DL Daniel Kripke reported in the journal Psychosomatic Medicine,demonstrate that people who want to get a good night's rest may not need to set aside more than 8 hours a night.He added that“it might be a good idea” for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed,but cau-tioned that more research is needed to confirm this.4 Previous studies have shown the potential dangers of chronic shortages of sleep一for instance,one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more.5 For the current report,Kripke reviewed the responses of 1,004 adults to sleep ques-tionaires,in which participants indicated how much they slept during the week and whether they experienced any sleep problems. Sleep problems included waking in the middle of the night,arising early in the morning and being unable to fall back to sleep,and having fatigue interfere with day-to-day functioning.6 Kripke found that people who slept between 9 and 10 hours each night were more like-ly to report experiencing each sleep problem than people who slept 8 hours. In an interview, Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence,he added that one way to help insomnia is to spend less time in bed.“It stands to reason that if a person spends too long a time in bed,then they'll spend a higher percentage of time awake.”he said. Paragraph 5______
[多选题]共用题干 Young Adults Who Exercise Get Higher IQ ScoresYoung adults who are fit have a higher IQ and are more likely to go on to university,reveals a major new study_________(51)out at the Sahlgrenska Academy and Sahlgrenska University Hospital.The results were recently published in the Proceedings of the National Academy of Sciences(PNAS).The study__________(52)1._________(1.)2 million Swedish men doing military service who were born between 1950 and1976._________(1976.)The research group analyzed the ________(53)of both physical and IQ tests the youngsters took right after they started serving the army.The study shows a clear link _________(54)good physical fitness and better results for the IQ test.The strongest links are for ________(55)thinking and verbal comprehension.But it is only fitness thatplays a _________ (56)in the results for the IQ test,and not strength."Being fit means that you also havegood heart and lung __________(57)and that your brain gets plenty of oxygen."says Michael Nilsson,pro-fessor at the Sahlgrenska Academy and chief physician at the Sahlgrenska University Hospital."This may be one of the reasons why we can see a clear link with fitness,but not with muscular_________(58).We are also seeing that there are growth factors that are important."By analyzing data for twins,the researchers have been________(59)to determine that it is primarily environmental factors and not genes that___________(60)the link between fitness and a higher IQ."We have also shown that those youngsters who _______(61)their physical fitness between the ages of 1 5 and 1 8 increase their performance."says Maria Aberg,researcher at the Sahlgrenska Academy andphysician at Aby health centre."This being the case,physical education is a_______(62)that has an important place in schools,and is an absolute must________(63)we want to do well in math and other theoretical subjects."The researchers have also compared the results from fitness tests during national service_______(64) the socioeconomic status of the men later in life.Those who were fit at I 8 were more__________(65)to go into higher education,and many secured more qualified jobs. _________(61)
[多选题]共用题干 第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results." It can be inferred from Mark Allen's address that_____________.
[多选题]共用题干 Hurricane1 A hurricane(飓风)is a tropical storm with winds that have reached a constant speed of 74 miles per hour. Hurricane winds blow in a large spiral(螺旋)around a relative calm center know as the“eye”.The“eye” is generally 20 to 30 miles wide,and the storm may ex- tend outward 400 miles. As a hurricane nears land,it can bring heavy rains,high winds,and storms(风暴潮).The storm surges and heavy rains can lead to flooding.2 Hurricanes are given a different label,depending on where they occur. If they begin over the North Atlantic Ocean,the Caribbean Sea,the Gulf of Mexico,or the Northeast Pa-cific Ocean,they are called hurricanes.Similar storms that occur in the Northwest Pacific Ocean west of the International Date Line are called typhoon. Near Australia and in the India Ocean, they are referred to as tropical cyclones(龙卷风).3 When a hurricane hits land,it can do great damage through its fierce winds,heavy rains , inland(内陆的)flooding, and huge waves crashing onto the shore. During a hurri-cane,homes,businesses,and public buildings may be damaged or destroyed;road and bridges can be washed away. A powerful hurricane can kill more people and destroy more property than any other natural disaster. Fishermen are at special risk from hurricanes as they may be at sea when a hurricane arrives and not be able to get to a safe harbour if they do not receive adequate warning.4 If a hurricane is coming in your area,the most important thing is to stay calm and find shelter immediately. Go to your safe room. If you do not have one,stay indoors during the hurricane and go to a safer place near the center of your home. Cover yourself with a blanket and be sure to keep away from windows and glass doors,because if the glass breaks it's real-ly dangerous. Do not be fooled if there is a lull(暂停);it could be the eye of the storm-winds will pick up again. A powerful hurricane may become the most destructive________.
[多选题]共用题干 Eastern Quakes Can Trigger Big ShakesIn the first week of November 2011,people in central Oklahoma experienced more than two dozen earthquakes. The largest,a magnitude 5 .6 quake,shook thousands of fans in a college football stadium,caused cracks in a few buildings and rattled the nerves of many people who had never felt a quake before. Oklahoma is not an area of the country famous for its quakes. If you watch the news on TV,you see reports about all sorts of natural disasters一 hurricanes,tornadoes,flooding and wildfires,to name a few. But the most dangerous type of natural disaster,and also the most unpredictable,is the earthquake.Researchers at the U. S. Geological Survey estimate that several million earthquakes rattie the globe each year. That may sound scary,but people don't feel many of the tremors because they happen in remote and unpopulated regions.Many quakes happen under the ocean, and others have a very small magnitude,or shaking intensity.A magnitude 5.8 earthquake that struck central Virginia the afternoon of August 23, 2011,was felt from central Georgia to southeastern Canada. In many urban areas,including Washington,D.C.,and New York City(Wall Street shown),people crowded the streets while engineers inspected buildings.Scientists know about small,remote quakes only because of very sensitive electronic devices called seismometers.These devices detect and measure the size of ground vibrationsproduced by earthquakes.Altogether,USGS researchers use seismometers to identify and locate about 20,000 earthquakes each year.Although earthquakes can happen anywhere in the world,really big quakes occur only in certain areas. The largest ones register a magnitude 8 or higher and happen,on average,only once each year. Such big ones typically occur along the edges of Earth's tectonic plates.Tectonic plates are huge pieces of Earth's crust,sometimes many kilometers thick. These plates cover our planet's surface like a jigsaw puzzle. Often,jagged edges of these plates temporarily lock together. When plates jostle and scrape past each other,earthquakes occur. On average,tectonic plates move very slowly一about the same speed as your fingernails grow.But sometimes earthquakes rumble through portions of the landscape far from a plate's edges. Although less expected,these”mid-plate” tremors can do substantial damage. Some of the biggest known examples rattled the eastern half of the United States two centuries ago. Today,scientists are still puzzling over why the quakes occurred and when similar ones might occur. Oklahoma is an area often experiencing natural disasters.
[多选题]共用题干 第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results." What do scientists claim to have found about Saturn?
[多选题]共用题干 Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life. Schmidt and her colleagues are the first group of scientists reaching Europ
[多选题]共用题干 Ford1 Ford's great strength was the manufacturing process一not invention.Long before he started a car company,he was a worker,known for picking up pieces of metal and wireand turning them into machines.He started putting cars together in 1891.Although it was by no means the first popular automobile,the Model T showed the world just how creative Ford was at combining technology and market.2 The company's assembly line alone threw America's Industrial Revolution into overdrive (高速运转).Instead of having workers put together the entire car, Ford's friends, who were great toolmakers from Scotland,organized teams that added parts to each Model T as it moved down a line. By the time Ford's Highland Park plant was humming(嗡嗡作响) along in 1914,the world's first automatic conveyor belt could turn out a car every 93 minutes.3 The same year Henry Ford shocked the world with the$5-a-day minimum wage scheme,the greatest contribution he had ever made.The average wage in the auto industry then was$2.34 for a 9-hour shift.Ford not only doubled that,he also took an hour off the workday.In those years it was unthinkable that a man could be paid that much for doing something that didn't involve an awful lot of training or education.The Wall Street Journal called the plan"an economic crime",and critics everywhere laughed at Ford.4 But as the wage increased later to daily$10,it proved a critical component of Ford's dream to make the automobile accessible(可及的)to all. The critics were too stupid to understand that because Ford had lowered his costs per car,the higher wages didn'tmatter一except for making it possible for more people to buy cars. Paragraph 2_________
[多选题]共用题干 Mother Nature Shows Her StrengthTornadoes(龙卷风)and heavy thunderstorms moved across the Great Lakes and into Trumbull County on Saturday evening.The storms were dramatic and dangerous.George Snyder was driving the fire truck down Route 88 when he first noticed that a funnel(漏斗状的)cloud was behind him. " I stopped the truck and watched the funnel cloud.It was about 1 00 feet off the ground and I saw it go up and down for a while.It was moving toward Bradley Road and then suddenly it disappeared,"Snyder said.Snyder only saw one of the funnel clouds that passed through northeastern Ohio on Saturday.In Trumbull County,a tornado turned trees onto their sides.Some trees fell onto houses and cars.Other trees fell into telephone and electrical wires as they went down.Amanda Symcheck was having a party when the storm began."I knew something was wrong , " she said."I saw the sky go green and pink(粉红色).Then it sounded like atrain rushing toward the house.I started crying and told everyone to go to the basement for protection."The tornado caused a lot of damage to cars and houses in the area.It will take a long time and much money to repair everything.There was also serious water damage from the thunderstorms.The heavy rains and high wind caused the power to go out in many homes.The storms caused serious flooding in areas near the river. More than four inches of rain fell in parts of Trumbull County.The river was so high that the water ran into streets and houses.Many streets had to be closed to cars and trucks because of the high water. This made it difficult for fire trucks,police cars,and other rescue vehicles to help peoplewho were in trouble.Many people who live near the river had to leave their own safety.Some people reported five feet of water in their homes.Local and state officials openedemergency shelters for the people who were evacuated(撤走).The Red Cross served meals to them."This was a really intense storm,"said Snyder."People were afraid.Mother Nature can be fierce.We were lucky this time.No one was killed." There had not been such a severe storm in Trumbull County for a hundred years.
[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. iPad usage in offices enables employee productivity to be______________.
[多选题]共用题干 The Forbidden AppleNew York used to be the city that never sleeps. These days it's the city that never smokes,drinks or does anything naughty(at least,not in public).The Big Apple is quickly turning into the Forbidden Apple.If you wanted a glass of wine with your picnic in Central Park,could you have one?No chance. Drinking alcohol in public isn't allowed. If you decided to feed the birds with the last crumbs(碎屑)of your sandwich, you could be arrested. It's illegal. If you went to a bar for a drink and a cigarette,that would be OK,wouldn't it?Er…no.You can't smoke in public in New York City.What's going on?Why is the city that used to be so open-minded becoming like this?The mayor of New York is behind it all. He has brought in a whole lot of new laws to stop citizens from doing what they want,when they want.The press are shocked. Even the New York police have joined the argument. They re- cently spent$100,000 ona“Don't blame the cop”campaign. One New York police officer said,”We raise money for the city by giving people fines for breaking some very stupid laws. It's all about money.”The result is lot of fines for minor offences. Yoav Kashida,and Israeli tourist,fell asleep on the subway. When he woke up,two police officers fined him because he had fallen asleep on two seats(you mustn't use two seats in the subway).Elle and Serge Schroitman were fined for blocking a driveway with their car. It was their own driveway.The angry editor of Vanity Fair magazine,Graydon Carter,says.”Under New York City law it is acceptable to keep a gun in your place of work,but not an empty ashtray.”He should know. The police came to his office and took away his ashtray(烟灰缸).But not all of New York's inhabitants are complaining. Marcia Dugarry,72,said,”The city has changed for the better. If more cities had these laws,America would be a better place to live.”Nixon Patotkis,38,a barman,said,”I like the new laws. If people smoked in here, we'd go home smelling of cigarettes.”Recent figures show that New York now has fewer crimes per 100,000 people than 193 other US cities.And it's true一It's safer,cleaner and more healthy than before. But let'sbe honest一who goes to New York for its clean streets? New York is cleaner and safer than before.
[多选题]共用题干 Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles(束)of electromagnetic(电磁)energy called photons(光子).Today,scientists agree that light has a dual(二重)nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference(干扰), etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel(旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum(真空),however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane. Some instances such as reflection and absorption can change______.
[多选题]共用题干 第三篇Cell Phones : Hang Up or Keep Talking?Millions of people are using cell phones today.In many places it is actually considered unusual not to use one.In many countries,cell phones are very popular with young people.They find that the phones are more than a means of communication一having a mobile phone shows that they are cool and connected.The explosions around the world in mobile phone use make some health professionals worried.Some doctors are concerned that in the future many people may suffer health problems from the use of mobile phones.In England,there has been a serious debate about this issue.Mobile phone companies are worried about the negative publicity of such ideas.They say that there is no proof that mobile phones are bad for your health.On the other hand,why do some medical studies show changes in the brain cells of some people who use mobile phones?Signs of change in the tissues of the brain and head can be detected with modern scanning (扫描)equipment. In one case , a traveling salesman had to retire at a young age because of serious memory Loss.He couldn't remember even simple tasks.He would often forget the name of his own son.This man usedto talk on his mobile phone for about six hours a day,every day of his working week,for a couple of years.His family doctor blamed his mobile phone use,but his employer's doctor didn't agree.What is it that makes mobile phones potentially harmful?The answer is radiation.High-tech machines can detect very small amounts of radiation from mobile phones.Mobile phone companies agree that there is some radiation,but they say the amount is too small to worry about.As the discussion about their safety continues,it appears that it's best to use mobile phones less often. Use your regular phone if you want to talk for a long time.Use your mobile phone only when you really need it.Mobile phones can be very useful and convenient,especially in emergencies.In the future,mobile phones may have a warning label that says they are bad for your health.So for now,it's wise not to use your mobile phone too often. The writer's purpose of wnting this article is to advise people__________.
[多选题]共用题干 Young Adults Who Exercise Get Higher IQ ScoresYoung adults who are fit have a higher IQ and are more likely to go on to university,reveals a major new study_________(51)out at the Sahlgrenska Academy and Sahlgrenska University Hospital.The results were recently published in the Proceedings of the National Academy of Sciences(PNAS).The study__________(52)1._________(1.)2 million Swedish men doing military service who were born between 1950 and1976._________(1976.)The research group analyzed the ________(53)of both physical and IQ tests the youngsters took right after they started serving the army.The study shows a clear link _________(54)good physical fitness and better results for the IQ test.The strongest links are for ________(55)thinking and verbal comprehension.But it is only fitness thatplays a _________ (56)in the results for the IQ test,and not strength."Being fit means that you also havegood heart and lung __________(57)and that your brain gets plenty of oxygen."says Michael Nilsson,pro-fessor at the Sahlgrenska Academy and chief physician at the Sahlgrenska University Hospital."This may be one of the reasons why we can see a clear link with fitness,but not with muscular_________(58).We are also seeing that there are growth factors that are important."By analyzing data for twins,the researchers have been________(59)to determine that it is primarily environmental factors and not genes that___________(60)the link between fitness and a higher IQ."We have also shown that those youngsters who _______(61)their physical fitness between the ages of 1 5 and 1 8 increase their performance."says Maria Aberg,researcher at the Sahlgrenska Academy andphysician at Aby health centre."This being the case,physical education is a_______(62)that has an important place in schools,and is an absolute must________(63)we want to do well in math and other theoretical subjects."The researchers have also compared the results from fitness tests during national service_______(64) the socioeconomic status of the men later in life.Those who were fit at I 8 were more__________(65)to go into higher education,and many secured more qualified jobs. _________(56)
[多选题]共用题干 Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life. The formations on Europa's surface are rather unique in the universe.
[多选题]共用题干 Flying into HistoryWhen you turn on the television or read a magazine , celebrities(名人)are everywhere. Although fame and the media play such major roles in our lives today,it has not always been that way._______________(46) Many historians agree that Charles Lindbergh was one of the first major celebrities,or superstars.Lindbergh was born in Detroit,Michigan,in 1902,but he grew up in Little Falls,Minnesota. As achild,he was very interested in how things worked,so when he reached college,he pursued a degree in en- gineering. At the age of 20, however, the allure(诱惑)of flying captured Lindbergh' s imagination. _______________(47)Soon after,Lindbergh bought his own plane and traveled across the nation performing aerial stunts(空中特技).In 1924,Lindbergh became more serious about flying. He joined the United States military and graduated first in his pilot class._______________(48)During the same time,a wealthy hotel owner named Raymond Orteig was offering a generous award to the first pilot who could fly nonstop from New York City to Paris,France.The Orteig Prize was worth $25,000一a large amount even by today's standards.Lindbergh knew he had the skills to complete the flight,but not just any plane was capable of flyingthat far for that long.______________ (49)On May 20,1927,Charles Lindbergh took off from Roosevelt Field in New York City and arrived the next day at an airstrip(简易机场)outside Paris. Named in honor of the sponsor , The Spirit of St. Louis car- ried Lindbergh across the Atlantic Ocean and into the record books.He became a national hero and a huge celebrity.When he returned to the United States , Lindbergh rode in a ticker-tape(热烈的)parade held to cele- brate his accomplishment._______________(50)A very popular dance was even named for Charles Lindbergh一 the Lindy Hop.Today,The Spirit of St. Louis is kept at the Smithsonian institute'5 National Air and Space Museum in Washington,D.C. _________(49)
[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. At the starting stage the EoL will get information from_______________.
[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 machines 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一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 lab- mates 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's team programmed 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 then tested the robot in pigs.A company called Medrobotics in Boston is now adapting the technology to surgeries on people.Even after 15 years of working with his team's creations,”I still don't get bored of watching the motion of my robots,”Choset says. Choset began to build robots in high school.
[多选题]共用题干 Ford1 Ford's great strength was the manufacturing process一not invention.Long before he started a car company,he was a worker,known for picking up pieces of metal and wire and turning them into machines.He started putting cars together in 1891.Although it was by no means the first popular automobile,the Model T showed the world just how creative Ford was at combining technology and market.2 The company's assembly line alone threw America's Industrial Revolution into overdrive (高速运转).Instead of having workers put together the entire car , Ford's friends , who were great toolmakers from Scotland,organized teams that added parts to each Model T as it moved down a line. By the time Ford's Highland Park plant was humming(嗡嗡作响) along in 1914,the world's first automatic conveyor belt could turn out a car every 93 minutes.3 The same year Henry Ford shocked the world with the$5-a-day minimum wage scheme,the greatest contribution he had ever made. The average wage in the auto industry thenwas $2.34 for a 9-hour shift. Ford not only doubled that,he also took an hour off the workday.In those years it was unthinkable that a man could be paid that much for doing something that didn't involve an awful lot of training or education.The Wall Street Journal called the plan"an economic crime",and critics everywhere laughed at Ford.4 But as the wage increased later to daily$10,it proved a critical component of Ford's dream to make the automobile accessible(可及的)to all. The critics were too stupid to understand that because Ford had lowered his costs per car,the higher wages didn't matter一 except for making it possible for more people to buy cars. Higher wages enabled many people to_______.
[多选题]共用题干 第三篇Small but WiseOn December 14,NASA blasted a small but mighty telescope into space.The telescope is called WISE and is about as wide around as a trashcan.Don't let its small size fool you:WISE has a powerful digital camera,and it will be taking pictures of some of the wildest objects in the known universe,including asteroids,faint stars,blazing galaxies and giant clouds of dust where planets and stars are born."I'm very excited because we're going to be seeing parts of the universe that we haven't seen be- fore,"said Ned Wright,a scientist who directs the WISE project.Since arriving in space,the WISE telescope has been circling the Earth,held by gravity in a polar orbit (this means it crosses close to the north and south poles with each lap).Its camera is pointed outward,awayfrom the Earth,and WISE will snap a picture of a different part of the sky every 11 minutes.After six months it will have taken pictures across the entire sky.The pictures taken by WISE won't be like everyday digital photographs,however. WISE stands for "Wide-field Infrared Survey Explorer".As its name suggests,the WISE camera takes pictures of features that give off infrared radiation.Radiation is energy that travels as a wave.Visible light,including the familiar spectrum of light that be- comes visible in a rainbow,is an example of radiation.When an ordinary digital camera takes a picture of a tree,for example,it receives the waves of visible light that are reflected off the tree.When these waves enter the camera through the lens,they're processed by the camera,which then puts the image together.Waves of infrared radiation are longer than waves of visible light,so ordinary digital cameras don't see them,and neither do the eyes of human beings.Although invisible to the eye,longer infrared radiation can be detected as warmth by the skin.That's a key idea to why WISE will be able to see things other telescopes can't. Not everything in the universe shows up in visible light.Asteroids,for example, are giant rocks that float through space一but they absorb most of the light that reaches them.They don't reflect light,so they're difficult to see.But they do give off infrared radiation,so an infrared telescope like WISE will be able to produce images of them.During its mission WISE will take pictures of hundreds of thousands of asteroids.Brown dwarfs are another kind of deep-space objects that will show up in WISE's pictures.These ob- jects are "failed" stars一which means they are not massive enough to jump-start the same kind of reactions that power stars such as the sun.Instead,brown dwarfs simply shrink and cool down.They're so dim that they're almost impossible to see with visible light,but in the infrared spectrum they glow. It can be inferred from the last paragraph that brown dwarfs__________.
[多选题]共用题干 Ford1 Ford's great strength was the manufacturing process一not invention.Long before he started a car company,he was a worker,known for picking up pieces of metal and wire and turning them into machines.He started putting cars together in 1891.Although it was by no means the first popular automobile,the Model T showed the world just how creative Ford was at combining technology and market.2 The company's assembly line alone threw America's Industrial Revolution into overdrive (高速运转).Instead of having workers put together the entire car , Ford's friends , who were great toolmakers from Scotland,organized teams that added parts to each Model T as it moved down a line. By the time Ford's Highland Park plant was humming(嗡嗡作响) along in 1914,the world's first automatic conveyor belt could turn out a car every 93 minutes.3 The same year Henry Ford shocked the world with the$5-a-day minimum wage scheme,the greatest contribution he had ever made. The average wage in the auto industry thenwas $2.34 for a 9-hour shift. Ford not only doubled that,he also took an hour off the workday.In those years it was unthinkable that a man could be paid that much for doing something that didn't involve an awful lot of training or education.The Wall Street Journal called the plan"an economic crime",and critics everywhere laughed at Ford.4 But as the wage increased later to daily$10,it proved a critical component of Ford's dream to make the automobile accessible(可及的)to all. The critics were too stupid to understand that because Ford had lowered his costs per car,the higher wages didn't matter一 except for making it possible for more people to buy cars. The assembly line made it possible to_______.
[多选题]共用题干 Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive(原始的)man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship(崇拜)a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve(曲线)of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling(闪烁)lights. Some early astronomers(天文学家)believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it. Early man thought the earth was small and flat because_________.