题目
题型：不详难度：来源：
More than 62,000 people in the U．S. alone are waiting to ____ donated hearts，lungs and so on.The number of human donors falls far short of ____.Pig organs are of a(n) ____ size to human organs，and some scientists hope they might be used to help meet the ____.But previous attempts to transplant pig tissue into humans have ____.
The five pigs ____ a gene that adds a sugar to the surface of pig cells.The sugar would ____ immune(免疫的) rejection of the tissue.“This advance provides a neartime ____ for overcoming the problem that there is not enough human organs for transplants，”says an expert.“This is the ____ gene for overcoming the ____ stage of rejection.”
____，scientists warn that much more work is necessary ____ organs from copies of the pigs could be transplanted into humans.Human genes will need to be added，to ____ rejection of the organ in the long term.There are also ____ that pig viruses could infect patients.
Cloning techniques were ____ to the production of the pigs.Genes can only be knocked out(去除) in a single cell.Cloning of these single cells then allowed the ____ of a whole animal in which the gene was knocked out in every cell.But the PPL researchers have ____ in knocking out only one copy of the gene.The team will now attempt to knock out both copies of the gene.
The team will also ____ tests to investigate whether a virus from the pigs could infect human cells.“Although a lot of the work is very ____，we’re still very far off being able to grow an organ，” says Julia，who is working on this project and quite ____ to creating similar knockout pigs with researchers at the University of Missouri.
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答案
小题1:C
小题2:D
小题3:A
小题4:B
小题5:C
小题6:A
小题7:C
小题8:D
小题9:A
小题10:C
小题11:B
小题12:C
小题13:A
小题14:D
小题15:A
小题16:B
小题17:A
小题18:B
小题19:C
小题20:D
解析
小题1: D
解析 由本段内容可知，应是等待接受器官的移植。
小题2: B
解析 器官捐献不能满足人们的需求，demand符合语境。
小题3: C
解析 根据上下文可知，克隆猪的器官可以被移植到人体内，它们的器官应该和人类的器官大小相似。
小题4: A
解析 根据本段第二句“The number of human donors falls far short of ____.”可知，克隆猪的器官是为了弥补人类可移植器官的不足。
小题5: B
解析 上一句提到科学家期望克隆猪的器官能够应用于人类器官移植领域，but表示转折，说明以前类似的试验失败了。
小题6: A
解析 由下文“...a gene that adds a sugar to the surface of pig cells.The sugar would ____ immune(免疫的) rejection of the tissue.”可推测，这一基因会导致不好的结果，又根据“‘This advance provides...’”可知，这五只克隆猪没有这一基因，因此选lack。
小题7: B
解析 根据上下文可知，这种糖分可能会使器官产生免疫排斥，cause符合语境。
小题8: D
解析 根据后面overcoming the problem的提示，可知对人类可移植器官不足的问题提供了一个解决办法。
小题9: C
解析 根据上文“...a gene that adds a sugar to the surface of pig cells.”可知，这一基因对克服器官排斥问题很关键，所以选key。
小题10: D
解析 根据下一段第二句“Human genes will need to be added，to ____ rejection of the organ in the long term.”可知，对这一基因的处理只能解决器官排斥早期的一些问题。
小题11: A
解析 根据下文“...scientists warn that much more work is necessary...”可知，本段内容与上一段意思是转折关系，所以用however。
小题12: B
解析 根据下文“Human genes will need to be added...”可知，在克隆猪的器官可以移植到人体内之前，还有很多工作要做，所以用before。
小题13: A
解析 根据上下文可知，科学家们的这些工作是为了防止器官排斥。
小题14: C
解析 由句意可知，猪身上的病毒可能会感染病人，这是人们所担心的。
小题15: B
解析 这五只猪是克隆动物，显而易见，克隆技术对繁育出这几只猪至关重要，vital符合语境。
小题16: D
解析 基因的去除只有在单个细胞中才能进行，克隆这些单细胞然后再将其培育成一只完整的动物，这样动物身上的每个细胞中的这种基因就都被去除了，creation符合语境。
小题17: B
解析 根据下文“The team will now attempt to knock out both copies of the gene.”可知，PPL researchers已经成功去除这种基因的一个副本。
小题18: A
解析 句意为：这一团队还将进行试验研究克隆猪身上的细菌是否会感染人体。conduct tests进行试验。
小题19: C
解析 although表示让步，根据主句“‘we’re still very far off being able to grow an organ，’”可知，exciting符合语境。
小题20: C
解析 Julia致力于培育这种去除基因的克隆猪，devoted符合语境。
核心考点
试题【Five cloned pigs，whose organs are much less likely to be rejected(排斥) by a patie】；主要考察你对题材分类等知识点的理解。[详细]
举一反三
Plastic as a material enjoys the biggest demand in the modern world，but it does have a number of drawbacks.First and foremost，plastic isn’t recyclable.Secondly，it contains toxins (毒物) helping develop cancerous diseases.Finally，it’s made of oil and oil reserves aren’t endless.
The liquid wood technology is likely to replace plastic and provide mankind with new materials for many years ahead.Norbert Eisenfreich，a senior researcher at the Faunhofer Institute for Chemical Technology (ICT) in Germany，said that arboform，the new material，is made of lignin (木质素)，which can be obtained from soft tissues of wood.Once mixed with several other materials，it turns into solid and nontoxic alternative for plastics.
ICT team leader Emilia Regina InoneKauffmann said the woodworking industry separates wood into three basic components，including lignin.Lignin isn’t used for the production of paper.Specialists of ICT mixed lignin with several natural materials and thus invented the material which could be melted and molded (铸型)．
When solid，arboform looks like plastic and possesses the qualities of polished wood.It can be used for the production of any items.Arboform is already used for the production of car parts which require extra strength.In addition，liquid wood can be recycled repeatedly.The material preserved all of its qualities even if it’s reprocessed ten times.
However，the new invention doesn’t enjoy an extensive use due to the high content of sulphur (硫) in it.German researchers are sure to reduce the amount of sulphur by 90 percent very soon to make arboform usable for home needs.
小题1:According to the passage，plastic________.
| A．plays a big role in the modern world |
| B．helps to protect our environment in some way |
| C．has been replaced by the newly discovered material |
| D．helps us to reduce the use of petrol |
| A．It is easily made from natural oil. |
| B．It is more widely used in household. |
| C．It is recyclable and friendly to the environment. |
| D．It contains no poisonous materials. |
| A．the material’s extensive use |
| B．the content of sulphur in arboform |
| C．the production cost of arboform |
| D．the qualities of liquid wood |
| A．advertise the new material—arboform |
| B．introduce liquid wood which will replace plastic |
| C．advertise new products made of arboform |
| D．show readers how to produce arboform |
One of the longest is the Appalachian National Scenic Trail.The trail is the first completed part of the National Trails System.The trails system was established by Congress and the president in 1968.The Appalachian Trail is more than 3,400 kilometers long.It starts in the northeastern state of Maine and ends in the southeastern state of Georgia.The trail goes through 14 states.They are Maine，New Hampshire，Vermont，Massachusetts，Connecticut，New York，New Jersey，Pennsylvania，Maryland，West Virginia，Virginia，Tennessee，North Carolina，and Georgia.
The path takes walkers through the Appalachian Mountains.They extend from the Canadian province of Quebec to the southern American state of Alabama.
The Appalachian Mountains are among the oldest on Earth.They first began forming about one thousand million years ago.During the millions of years since then，the mountains were changed and reformed by the forces of water and wind.Ice also changed the mountains，making many of them smaller and digging valleys and lakes among them.Many different kinds of trees grow along the trail.And many different kinds of animals live in the forests along the trail.
Lands along the trail are protected by the federal government and by state governments.Some parts are not protected by the government directly.Instead，they are protected by legal agreements with private owners willing to permit people to walk across their property.
Walkers on the Appalachian Trail pass through some of the great valley systems of the mountains.They can look down into these beautiful valleys and see farms and forests stretching across the land for many kilometers.Farmland in the valleys is rich and productive.And some of the great events in American history took place in the valleys.For example，one of the great battles of the American Civil War was fought in the Shenandoah Valley in Virginia.
小题1:The Appalachian Trail________.
| A．is more than four thousand three hundred kilometers long |
| B．starts in the northern state of Maine |
| C．goes through more than fourteen states |
| D．ends in the southeastern state of Georgia |
| A．are the first completed part of the National Trails System |
| B．began forming one million years ago |
| C．were changed by natural forces like water，wind and ice |
| D．were around by valleys and rivers and famous for its scenery |
| A．are protected entirely by either the federal government or state governments |
| B．are mainly protected by legal agreements with private owners |
| C．can be visited by travelers freely only under the permission of owners |
| D．are protected by both the federal government and state governments |
| A．The Appalachian Mountains have some great valley systems. |
| B．Farms and grasslands stretch across the valleys for many kilometers. |
| C．One of the American independence battles was fought in the Shenandoah Valley. |
| D．Lakes in the Appalachian Mountains are one of the most beautiful sights. |
It’s a message that many a mom and dad have tried to impress upon many a youngster (and some notsoyoungsters) who spend perhaps a bit too much time with game controllers in hand.
But the 40yearold Langteau isn’t a parent.He’s a veteran (老手) of the video game industry—one who played producer on three “Medal of Honor” games and cofounded his own game development company.
Langteau has just published a children’s books called Sofa Boy，which tells the story of a kid who spends too much time sitting on the couch with controller clutched in hand and the rather terrible consequences that follow.
It’s a fairy tale plucked straight from Langteau’s own experiences as a lad with a fondness for video games and his own bouts with a bit of game addiction.But first，Langteau would like to make one thing clear，“I’m not saying that you shouldn’t play video games.I think video games are great.I think they do great things for kids.”Instead，Langteau says his book is all about a little something called moderation (克制)．
“It’s about being well rounded，” he says.“Just like with anything else，we all need to make sure that there’s a variety in what we do.”
Video gamers can be rather badtempered when it comes to accepting criticism about their favorite entertainment.And understandably so.After all，most people who go around talking about the dangers of playing video games tend to be outsiders—people who don’t play video games and certainly don’t understand that they can be a valuable and healthy form of entertainment.
But Langteau and Sofa Boy seem to be in a unique position to deliver a message of gaming moderation that the young game masses might actually listen to.After all，this is a man who understands what it means to be a kid with a passion for games.His early experience has taught him a lesson.
小题1:Scott Langteau published Sofa Boy to________.
| A．share his great skills on games |
| B．warn kids against game addiction |
| C．tell about his fairy tale as a kid |
| D．deliver a message for video games |
| A．The book implies the writer’s own story. |
| B．The book describes a veteran of games. |
| C．The boy in the book wins a medal in games. |
| D．The boy in the book is not a video game addict. |
| A．Langteau advises the young to play games within limits |
| B．Langteau advises the young not to play games |
| C．playing video games ruins the future of kids |
| D．playing video games doesn’t benefit kids |
| A．games do great good to kids |
| B．gamers are usually fat and round |
| C．games should be viewed from all sides |
| D．gamers are to blame for their behaviors |
I was even more surprised to learn that my son is normal.“Teenagers with cellphones each send and receive 2,272 text messages a month on average，” Nielsen Mobile says.
Some experts regret that all that keyboard jabber is making our kids stupid，unable to read nonverbal cues such as facial expressions，gestures，posture and other silent signals of mood and attitude.Unlike phones，text messaging doesn’t even allow transmission of tone of voice or pauses，says Mark Bauerlein，author of a book called The Dumbest Generation：How the Digital Age Stupefies Young Americans and Jeopardizes Our Future.
Beyond that，though，I’m not sure I see as much harm as critics of this trend.I’ve posted before on how I initially tried to control my kids’ texting.But over time，I have seen my son suffer no apparent ill effects，and he gains a big benefit，of easy，continuing contact with others.
I don’t think texting make kids stupid.It may make them annoying，when they try to text and talk to you at the same time.And it may make them distracted，when buzzing text messages interrupt efforts to noodle out a math problem or finish reading for school.
But I don’t see texting harming teens’ability to communicate.My son is as accustomed to nonverbal cues as any older members of our family.I have found him more engaged and easier to communicate with from a great distance，because he is constantly available via text message and responds with faithfulness and speed.
小题1:What does the underlined word “distracted” in the fifth paragraph mean?
| A．Confused. | B．Absentminded. |
| C．Comfortable. | D．Badtempered. |
| A．For Teens，Texting Instead of Talking |
| B．For Parents，Caring Much for Their Kids |
| C．Advantages and Disadvantages of Texting |
| D．The Effect of Communication |
| A．objective | B．opposed |
| C．supportive | D．doubtful |
| A．It is normal for a teen to send or receive 60 text messages a day. |
| B．Texting is a very popular way of communication among teens. |
| C．When texting，teens never mind talking with others. |
| D．The writer limited his son to send or receive text messages at first. |
People in California love to talk about “zeroemissions vehicles”，but_people_in_California_seem_to_be_clueless_about_where_electricity_comes_from.Power plants mostly use fire to make it.Aside from the new folks who have their roofs covered with solar cells，we get our electricity from generators.Generators are fueled by something—usually coal，oil，but also by heat generated in nuclear power plants.There are a few wind farms and geothermal(地热的) plants as well，but by far we get electricity mainly by burning something.
In other words，those “zeroemissions” cars are likely coalburning cars.It’s just because the coal is burned somewhere else that it looks clean.It is not.It’s as if the California Greens are covering their eyes—“If I can’t see it，it’s not happening.” Gasoline is an incredibly efficient way to power a vehicle；a gallon of gas has a lot of energy in it.But when you take that gas(or another fuel) and first use it to make electricity，you waste a nice part of that energy，mostly in the form of wasted heat—at the generator，through the transmission(传送) lines，etc.
A gallon of gas may propel your car 25 miles.But the electricity you get from that gallon of gas won’t get you nearly as far—so electric cars burn more fuel than gaspowered ones.If our electricity came mostly from nukes；or geothermal，or hydro，or solar，or wind，then an electric car truly would be clean.But for political，technical，and economic reasons，we don’t use much of those energy sources.
In addition，electric cars’ batteries which are poisonous for a long time will eventually end up in a landfill.And finally，when cars are the polluters，the pollution is spread across all the roads.When it’s a power plant，though，all the junk is in one place.Nature is very good at cleaning up when things are too concentrated，but it takes a lot longer when all the garbage is in one spot.
小题1:What does the underlined part mean in Paragraph 2?
| A．People see the California Greens everywhere. |
| B．People in California love to talk about zeroemissions vehicles. |
| C．People in California love to have their roofs covered with solar cells. |
| D．People in California have no idea that so far electricity mainly comes from burning coal，oil，etc. |
| A．Electric cars are not clean at all. |
| B．Electric cars are better than gasolinepowered ones. |
| C．People cast doubts on electric cars’ batteries. |
| D．Gasoline is an efficient way to power a vehicle. |
| A．not less than 25 miles |
| B．as far as 50 miles |
| C．as far as 25 miles |
| D．not more than 25 miles |
| A．being green is good and should be encouraged in communication |
| B．electric cars are not clean in that we get electricity mainly by burning something |
| C．zeroemissions vehicles should be chosen to protect our environment |
| D．electric cars are now the dominant vehicle compared with gasolinepowered cousins |
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