问题：共用题干 The Arctic Ice is ThawingFather Christmas may have to move his"workshop"from the North Pole because global warming isthawing the ice beneath his feet and his reindeers'feet as well.His"workshop"is in dire straits.The"plat- form"for the"workshop"is melting,said Stefan Norris of the World Wildlife Fund environmental group's Arctic Program.An eight-nation report by 250 scientists published recently predicted the Arctic Ocean could be ice-free in summer by 2100 because of a build-up of heat-trapping gases in the atmosphere,mainly from burning fossil fuels in cars or factories.The North Pole is getting more and more uninhabitable to Father Christmas. __________(46)Young people learn that Father Christmas'"workshop"produces millions of gifts delivered by him on a flying,reindeer-drawn sleigh.Hollywood movies like"The Polar Express"tried to make viewers believe that Father Christmas lives at the North Pole._______(47)The"Fortress of Solitude"is near the North Pole that could be under threat in a warmer world. Alan Boldt, spokesman of the Danish Ministry of Science,suggested ways to rescue Father Christmas._________(48) Another alternative,he argued,woald be building some electrical facilities to ensure the ice stays on the North Pole for him."This should be a subject for the United Nations,"he said."Danmark could build windmills to pro- vide Father Christmas with power."Denmark says Father Christmas'real home is Greenland,which will help, Denmark thinks,to strengthen its position in claiming the sovereignty over the Pole.__________(49)"Doesn't he already speak Danish?"Boldt said frostily when asked if Father Christmas would be forced to learn Danish if Denmark won international recognition of its claim to the Pole.Last month's Arctic report said the region is warming twice as fast as the rest of the globe,partly because dark ground or water,once un-covered,soaks up more heat than ice or snow.Finland has been most favored by Father Christmas and it has about 500,000 tourists a year to visit its Christmas center in Rovaniemi in Lapland._________(50)_________(49)A:However,Nordic nations all reject it by claiming that their countries are his home.B:Therefore the North Pole is the most attractive place in the world.C:If Denmark's claim were accepted internationally,it would have the legal right to search for oil and gas at the North Pole.D:One of them would be building a giant floating ice rink for the workshop if the Pole thaws.E:Maybe Father Christmas has already moved to Rovaniemi.F:He may have to move from the North Pole within our children's lifetimes.
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问题：共用题干 Save Energy At HomeOn the average,Americans waste as much energy as two-thirds of the world's population consumes.That's largely the_________(1)of driving inefficient cars,using inefficient appliances（设备）,and living and working in poorly insulated（隔热）buildings. Then what can you do to_________(2)the situation?Buy energy-efficient products一Buy new appliances or electronics of the highest energy-efficiency rating.New energy-efficient models may cost more initially,but have a lower operating ___________(3)over their lifetimes.The most energy-efficient models___________(4)the Energy Star label,which identifies products___________(5)use 20 -40 percent less energy than standard new products. According to the EPA（美国环境保护署）,the typical American household can save about $400 per year in___________(6)bills with products that carry the Energy Star.Switch to compact fluorescent bulbs（荧光灯）一Change the three bulbs you use ___________(7)in your house to compact fluorescents.Each compact fluorescent bulb will keep half a ton of CO2 out of the air___________(8)its lifetime.___________(9), compact fluorescent bulbs last ten times as long and can save $30 per year in electricity costs.Set heating and cooling temperatures correctly一Check thermostats（温度自动调节器）in your home to make sure they are___________(10)at a level that doesn't waste energy.Turn off the lights一Turn off lights and other electrical appliances such as televisions and radios when you're not___________(11)them.Install automatic timers for lights that people in your house frequently___________(12)to turn them off when leaving a room.Let the sun shine in一The cheapest and most energy-efficient light and heat source is often right outside your window. On___________(13) days, open blinds（百叶窗）to let the sun light your home for free.Also remember that___________(14)entering a room equals passive solar heating.Even on cold winter days,sun streaming into a room can raise the temperature by several___________(15)._________(1)A:power B:result C:way D:work
问题：共用题干 第一篇What Does GMO Free Mean?Genetically modified organisms(GMOs)in food are concern for a number of consumers who are worried about the impact that GMOs may have on their health.As a result,many companies in the late 1990s began to apply the GMO free label,indicating that their food does not contain genetically modified organisms.A number of nations legislate labeling,and in Europe,food must be labeled to indicate whether or not it contains GMOs.In the United States,however,GMO free labeling is purely voluntary and not regulated by any governmental body or organization.Since it is not regulated,there has been some question about the validity of the GMO free label in the US.A number of organizations have pressured the Food and Drug Administration(FDA),as well as the United States Department of Agriculture(USDA),to enact legislation governing food labeling in regards to GMOs.Many food activists want a label that is standardized,so that consumers who are concerned about this issue can be assured about the GMO content of products they purchase.Most US consumers have foods containing GMOs in their home.The majority of corn and soybeans grown in the US have been modified,as have several other crops.Some research indicates that many processed foods contain GMO ingredients,so for consumers who are concerned about this issue,GMO free labeling would be helpful.For consumers who want to eat natural,organic foods,knowing that the products they buy are GMO free is often very important. Although there is no federal labeling program in the US,some organic farmers and natural food producers have chosen to start their own certification programs.Getting certified through such programs can be very difficult,but many producers believe consumers will be willing to pay extra for the verification.The harmful nature of GMOs has been questioned,especially by commercial agriculture producers and seed providers.No scientific evidence has been found to suggest that genetic modification of crops is harmful to humans. Some consumers feel that it is important to be able to make conscious choices about what they eat,however,and want the ability to choose GMO free foods if they so desire.Some studies suggest that GMOs may be harmful to agriculture,with cloned genetically modified species harming overall biological diversity and modified genes finding their way into wild plants and non-modified crops.This is especially true in the case of corn,where GMO contamination became a major issue in the 1990s.Other research,however,indicates that genetically modified crops can be of benefit to the environment. Plants designed to be resistant to herbicides（除草剂）and pesticides （杀虫剂）,for example,have been seen to reduce the amount of these chemicals used by farmers on both GM and non-modified crops.A number of organizations in America have pressured the Food and Drug Administration(FDA) to______.A: ban foods containing GMOsB:punish commercial agriculture producers and seed providersC:enact legislation governing food labeling in regards to GMOsD:abolish legislation governing food labeling in regards to GMOs
问题：共用题干 第三篇Almost Human?Scientists are racing to build the world's first thinking robot.This is not science fiction: some say they will have made it by the year 2020.Carol Packer reports.Machines that walk,speak and feel are no longer science fiction.Kismet is the nameof an android（机器人）which scientists have built at the Massachusetts Institute of Technology(MIT).Kismet is different from the traditional robot because it can show human emotions.Its eyes,ears and lips move to show when it feels happy,sad or bored. Kismet is one of the first of a new generation of androids一robots that look like human beings一which can imitate human feelings.Cog,another android invented by the MIT, imitates the action of a mother. However,scientists admit that so far Cog has the mental ability of a two-year-old.The optimists（乐观主义者）say that by the year 2020 we will have created humanoids （机器人）with brains similar to those of an adult human being. These robots will be designed to look like people to make them more attractive and easier to sell to the public. What kind of jobs will they do?In the future,robots like Robonaut,a humanoid invented by NASA,will be doing dangerous jobs,like repairing space stations.They wi}{also be doing more and more of the household work for us.In Japan,scientists are designing androids that will entertain us by dancing and playing the piano.Some people worry about what the future holds:will robots become monsters（怪物）? Will people themselves become increasingly like robots?Experts predict that more and more people will be wearing micro-computers,connected to the Internet,in the future.People will have micro-chips in various parts of their body,which will connect them to a wide variety of gadgets（小装置）.Perhaps we should not exaggerate（夸大）the importance of technology,but one wonders whether,in years to come,we will still be falling in love, and whether we will still feel pain.Who knows?Kismet is different from traditional robots becauseA:it thinks for itself. B:itis not like science fiction.C:it can look after two-year-olds. D:it seems to have human feelings.
问题：共用题干 Wide World of RobotsEngineers who build and program robots have fascinating jobs. These researchers tinker（修补）with ma- chines in the lab and write computer software to control these devices."They're the best toys out there," says Howie Choset at Carnegie Mellon University in Pittsburgh.Choset is a roboticist,a person who designs, builds or programs robots.When Choset was a kid,he was interested in anything that moved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’。labmates were working on something even cooler than remotely controlled cars:robotic snakes.Some robots can move only forward, hackward, 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 robot、also moved in ways that snakes usually don't,such as rolling. Choset’s snake robots could crawl（爬行）through the grass,swini 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 theidea.Zenati practiced using the robot on a plastic model of the chest and they tested the robot in pigs. A company caikd Medrobotics in Boston is now adapting the technology for g urgerie9 on people-Even after 15 years of working with his team’s creations,"I still don't get bored of watching the motionof my robots,"Clioset says.Choset began to build robots in high school.A:RightB:WrongC:Not mentioned
问题：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______A: Online StoresB: Differences from iPhoneC: Display and Data ConnectionD: Business UsageE: Features and ApplicationsF: Operating System
问题：Michael is now merely a good friend,A:largely B:barely C:just D:rarely
问题：共用题干 The Fridge1.The fridge is considered a necessity.It has been so since the l960s when packaged food first appeared with the label:"Store in the refrigerator."2.In my fridgeless fifties childhood,I was fed well and healthily.The milkman came daily,the grocer,the butcher,the baker,and the ice-cream man delivered two or three times a week.The Sunday meat would last until Wednesday and surplus bread and milk became all kinds of cakes. Nothing was wasted and we were never troubled by rotten food.Thirty years on,food deliveries have ceased,fresh vegetables are almost unobtainable in the country.3.The invention of the fridge contributed comparatively little to the art of food preservation.A vast variety of well-tried techniques already existed一natural cooling,drying,smoking,slating, sugaring,bottling…4.What refrigeration did promote was marketing一marketing hardware and electricity,marketing soft drinks,marketing dead bodies of animals around the globe in search of a good price.5.Consequently,most of the world's fridges are to be found,not in the tropics where they might prove useful,but in the wealthy countries with mild temperatures where they are climatically almost unnecessary.Every winter,millions of fridges hum away continuously,and at vast expanse,busily maintaining an artificially-cooled space inside an artificially一heated house一while outside,nature provides the desired temperature free of charge.6.The fridge's effect upon the environment has been evident,while its contribution to human happiness has been insignificant. If you don't believe me,try it yourself. Invest in a food cabinet and turn off your fridge next winter. You may miss the hamburgers but at least you'll get ride of that terrible hum.Before fridges came into use,it was still possible for people to have fresh foods because_______.A:milk,meat,vegetables,etc.were deliveredB:it has promoted the sales of many kinds of commoditiesC:foods can be preservedD:most kids like iced soft drinksE:every housewife needs foodF: the fridge produced when it is working
问题：He led a very moral life.A:human B:intelligent C:natural D:honourable
问题：共用题干 第三篇Sugar Accelerate the Process of AgingSugar is widely used in our daily life to make food and drinks sweet,though too much intake of it may lead to diabetes.However,today's study found it also makes people get old faster. Rats that eat high levels of a natural sugar known as fructose seem to age faster than other rats.And the same could be true for people who eat too much sweet junk food,said Israeli researchers.Fructose,a substance found naturally in honey and fruit,is used widely in foods ranging from soft drinks to yogurt. But while its sweet taste is popular,the sugar could cause wrinkles and health problems,the researchers said.Dr. Moshe Werman and Boaz Levi of the Technion-Israel Institute of Technology fed large amounts of fructose to laboratory rats.Writing in the Journal of Nutrition,they said the fructose-fed rats showed changes in the collagen of their skin and bones.Collagen,a fibrous protein found in connective tissue,bone and cartilage,basically holds the body together. The loss of collagen is what causes sagging and deep wrinkles in older people.The process affected,Werman's team said,is known as"cross linking"."Too much crosslinking reduces elasticity and makes the skin stiff and rigid,and these are the conditions that encourage wrinkled skin,"Werman said in a statement. He said the same could be true of people, although this has not been shown."Americans are eating more and more processed foods such as carbonated drinks,baked goods,canned fruits,jams and dairy products that contain fructose," Werman said.Other studies have shown that high fructose intake can affect how the body handles glucose and increases insulin resistance一which can both be important measures of the tendency toward diabetes.The rats Werman worked with were fed much more than the average adult person might eat in a day,which is standard in such experiments.The rats were 12.5 grams of fructose per kg(2.2 pounds)of weight every day for a year. To compare,a person weighing 154 pounds(70kg)who drinks a quart(liter)of cola consumes about 60 grams of fructose,or 0.8 grams per kg of body weight.What does too much cross-linking lead to?A:Reduced strength.B:Blurred eyesight.C:Reduced elasticity and stiff and rigid skin.D:Tired muscles.
问题：共用题干 Computer Plug-in1.Life on the Internet can be enriched if you don't restrict yourself to just written words and still pictures.Even if you are a newcomer to the Internet world,you've probably heard about multi-media on-line一listening to radio,watching animations and videos,even playing in three-dimensional space.Sound and movement make information come alive.2.In order to experience that,some special pieces of software called plug-ins are necessary. The term"plug-in"refers to a small,add-on piece of software which extends the capabilities of your web browser,like Netscape Navigator or Microsoft Explorer,turning your computer into a radio or TV.3.When you open a web page with a file requiring a plug-in which you don't have.you will usually receive a message asking if you want to get it by downloading it and installing it into your computer. Most of the time,the installation will be automatic.4.Occasionally,you come across a downloaded file which needs to be decompressed or unzipped before installation.Once installed,plug-ins run automatically,without you having to do anything.5.Many multimedia controls still need to be obtained from the developer but are installed automatically.6.Shockwave is a typical example of it. All you need to do is go to the Macromedia site and click on the link to install the ActiveX control.The rest happens automatically.The next time you go to a"Shocked"website,the Shockwave control loads and plays the movie.7.Most plug-ins and controls can be downloaded for free on the Internet,although not all will work with every system.Some of them,for instance,only work with Windows 95.Once installed,plug-ins run_______,without you having to do anything.A:for free.B:freely.C:ability.D:automatically.E:Obtained.F:capability.
问题：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.In April 2010 the iPad developed by Apple was______.A: modifiedB: increasedC: personalizedD: browsedE: distributedF: released
问题：共用题干 What is the Coolest Gas in the Universe?What is the coldest air temperature ever recorded on Earth?Where was this low temperature recorded ?The coldest recorded temperature on Earth was －91℃, which_____ (51) in Antarctica（南极洲） in 1983.We encounter an interesting situation when we discuss temperatures in_________(52).Temperatures in Earth orbit（轨道）actually range from about +120℃ to －120℃. The temperature depends upon ______(53)you are in direct sunlight or in shade.Obviously，－120℃ is colder than our body can ________ (54)endure.The space temperatures just discussed affect only our area of the solar________(55).Obviously,it is hotter closer to the Sun and colder as we travel__________(56)from the Sun,Scientigtg egtimate tern- peratures at Pluto are about －210℃．How cold is the lowest estimated temperature in the entire universe?Again,it depends upon your_________(57).We are taught it is supposedly__________(58)to have atemperature below absolute zero,which is－273℃，at which atoms do not move.Two scientists,Cornell and Wieman,have successfully______(59)down a gas to a temperature barely above absolute zero. They won a Nobel Prize in Physics in 2001 for their work一not a discovery in this case.Why is the two scientists'work so important to science?In the 1920s，Satyendra Nath Bose was studying an interesting_______(60)about special light par-tidles（微粒）we now call photons（光子）.Bose had trouble __________(61)other scientists to believe his theory,so he contacted Albert Einstein. Einstein’s calculations helped him theorize that atoms_______(62) behave as Bose thought一but only at very cold temperatures.Scientists have also discovered that ultra-cold（超冷）atoms can help them make the world'S atomic clocks even__________(63)accurate.These clocks are so accurate today they would oniy lose one second _________ (64)six million years!Such accuracy will help us travel in space because digtanee is velocity（速度）times time( d=vt).With the long distances involved in space _______(65),we need to know time as accurately as possibie to get accurate distance._________(53)A:whetherB:whereC:whatD:when
问题：共用题干 Citizen ScientistsUnderstanding how nature responds to climate change will require monitoring key life cycle events-flowering,the appearance of leaves,the first frog calls of the spring-all around the world.But ecologists can't be______(51)so they are turning to non-scientists,sometimes called citizen scientists,for help.Climate scientists are not present everywhere.______(52)there are so many places in the world and not enough scientists to observe all of them,they are asking for your help in_______(53)signs of climate change across the world.The citizen scientist movement encourages______(54)people to observe a very specific research interest-birds,trees,flowers budding,etc-and send their observations______(55)a giant database to be observed by professional scientists.This helps a small number of scientists track a______(56)amount of data that they would never be able to gather on their own.______(57)like citizen journalists helping large publications cover a hyper-local beat,citizen scientists are ready for the conditions where they live.______(58)that's needed to become one is a few minutes each day or each week to gather data and_______(59)it in.A group of scientists and educators launched an organization last year______(60) the NationalPhenology（生物气候学）Network."Phenology" is what scientists call the study of the timing of events in nature.One of the group's first efforts relies on scientists and non-scientists______(61)to collect data about plant flowering and leafing every year.The program,called Project BudBurst,collects life cycle______(62)on a variety of common plants from across the United States.People participating in the project-which is______(63)to everyone-record their observations on the Project BudBurst website."People don't______(64)to be plant experts-they just have to look around and see what's in their neighborhood,"says Jennifer Scheartz,an education consultant with the project."As we collect this data,we'11 be able to make an'estimate of______(65)plants and communities of plants and animals will respond as the climate changes."_________62A:points B:wonders C:data D:interests
问题：共用题干 Motoring Technology1.2 million road deaths worldwide occur each year,plus a further 50 million injuries.To reduce car crash rate,much research now is focused on safety and new fuels-though some electric vehicle and biofuel research aims at going faster.Travelling at speed has always been dangerous.One advanced area of research in motoring safety is the use of digital in-car assistants.They can ensure you don't miss important road signs or fall asleep .Most crashes result from human and not mechanical faults.Some safety developments aim to improve your vision.Radar can spot obstacles in fog,while other technology"sees through"big vehicles blocking your view.And improvements to seat belts , pedal（脚踏）controls and tyres are making driving smoot- her and safer. The colour of a car has been found to be linked with safety,as have,less surpris- ingly,size and shape.But whatever is in the fuel tank,you don't want a thief in the driving seat and there have been many innovations（创新）.Satellite tracking and remote communications can also come into play if you crash,automatically calling for help.Accidents cause many traffic jams,but there are more subtle interplays between vehicles that can cause jams even on a clear but busy road.Such jams can be analyzed using statistical tools.Robotic drivers could be programmed to make traffic flow smoothly and will perhaps one day be everyone's personal chauffeur（司机）,but their latest efforts suggest that won't be soon. Which of the following safety developments is NOT mentioned in the passage?A: Windscreens that can help drivers to improve their vision.B: Radars that can help drivers to see obstacles in fog.C: Devices that can help drivers to see through big vehicles.D:Improvements in seat belts,pedal controls and tyres.
问题：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______.A: sources of lightB: the speed of lightC: the path of lightD: a straight lineE: a beam of lightF: a form of energy
问题： You will be meeting her presently.A:shortly B:currently C:lately D:probably
问题：The police believe the motive for the murder was jealousy.A:choice B:idea C:decision D:reason
问题：共用题干 When Our Eyes Serve Our StomachOur senses aren't just delivering a strict view of what's going on in the world;they're af-fected by what's going on in our heads. A new study finds that hungry people see food-related words more clearly than people who'ye just eaten.Psychologists have known for decades that what's going on,inside our head affects our senses. For example,poorer children think coins are larger than they are,and hungry people think pictures of food are brighter. Remi Radel of University of Nice Sophia-Antipolis,France,wanted to investi-gate how this happens. Does it happen right away as the brain receives signals from the eyes or a lit-tle later as the brain's high-level thinking processes get involved.Radel recruited 42 students with a normal body mass index. On the day of his or her test,each student was told to arrive at the lab at noon after three or four hours of not eating. Then they were told there was a delay. Some were told to come back in 10 minutes;others were given an hour to get lunch first. So half the students were hungry when they did the ex-periment and the other half had just eaten.For the experiment,the participant looked at a computer screen. One by one,80 words flashed on the screen for about 1/300th of a second each. They flashed at so small a size thatthe students could only consciously perceive. A quarter of the words were food-related. After each word,each person was asked how bright the word was and asked to choose which of two words they'd seen一a food-related word like cake or a neutral word like boat. Each word ap-peared too briefly for the participant to really read it.Hungry people saw the food-related words as brighter and were better at identifying food-related words. Because the word appeared too quickly for them to be reliably seen,this means that the difference is in perception,not in thinking processes,Radel says.“This is something great to me. Humans can really perceive what they need or what they strive for. From the experiment,I know that our brain can really be at the disposal of our mo-tives and needs,”Radel says.There was a delay in Radel's experiment because_______.A: he needed more students to joinB: he didn't prepare enough food for the 42 studentsC: he wanted two groups of participants,hungry and non-hungryD: he didn't want to have the experiment at noon
问题：共用题干 Dangers Await Babies with AltitudeWomen who live in the world's highest communities tend to give birth to under-weight ha-bies,a new study suggests.These babies may grow into adults with a high risk of heart disease and strokes.Research has hinted that newborns in mountain communities are lighter than average.But it wasn't clear whether this is due to reduced oxygen levels at high altitude or because their mothers are under-nourished—many people who live at high altitudes are relatively poor compared with those living lower down.To find out more,Dino Giussani and his team at Cambridge University studied the records of400 births in Bolivia during 1976 and 1998.The babies were born in both rich and poor areas of two cities:La Paz and Santa Cruz. La Paz is the highest city in the world,at 3 .65 kilometers a-bove sea level,while Santa Cruz is much lower,at 0.44 kilometers.Sure enough,Giussani found that the average birthweight of babies in La Paz was significant-ly lower than in Santa Cruz.This was true in both high and low-income families.Even babies born to poor families in Santa Cruz were heavier on average than babies born to wealthy families in lofty La Paz.“We were very surprised by this result,”says Giussani.The results suggest that babies born at high altitude are deprived of oxygen before birth. “This may trigger the release or suppression of hormones that regulate growth of the unborn child,”says Giussani.His team also found that high-altitude babies tended to have relatively larger heads compared with their bodies. This is probably because a fetus starved of oxygen will send oxygenated blood to the brain in preference to rest of the body.Giussani wants to find out if such babies have a higher risk of disease in later life.People born in La Paz might be prone to heart trouble in adulthood,for example.Low birth weight is a risk factor for coronary（冠状的）heart disease. And newborns with a high ratio of head size to body weight are often predisposed to high blood pressure and strokes in later life.What does the new study discover?A: Babies born to wealthy families are heaver.B:Women living at high altitude trnd to give birth to underweight babies.C: Newborns in cities are lighter than average.D: Low-altitude babies have a high risk of heart disease in later life.
