题目内容

17．Scientists have overcome a major difficulty for humans to receive life-saving organ transplants from pigs，thanks to a powerful new gene-editing technique．
In a paper in the US journal Science，the researchers described using gene-editing method to remove potentially harmful DNA sequences at 62locations，which are the remnants（留存之处） of a virus called PERV，from the pig genome．
Globally human organs for transplant being short in supply，researchers and doctors have long hoped that the problem could be solved through the availability of suitable animal organs for transplant，a concept known as xenotransplantation．
Pigs have been especially promising candidates due to their similar size and biological structure to humans．
But one of the largest safety concerns has been the fact that pigs，similar to most mammals，contain PERVs in all their living cells-that are harmless to their native hosts but can cause disease in other species．
"PERVs and the lack of ability to remove them from pig DNA was a real barrier on the promising stage set for xenotransplantation．"
In the new study，scientists made 62genetic edits to inactivate viruses in pig cells，which they called"an explosive leap forward"．
When these cells were then introduced to human cells in the lab，PERV infectivity was reduced by up to one thousand fold，they said．
"Our work got away the shadow PERVs put above the field more than a decade ago when the virus was discovered，while renewing our faith in xenotransplantation，"lead author Luhan Yang，a post-doctoral fellow at the Harvard University，said．
The team hopes eventually they can completely root out the risk that PERVs could cause disease in xenotransplantation by using modified pig cells to clone a line of pigs that would have their PERV genes inactivated．"We still have a long way to go，though．"Luhan added．

33．From the passage，we may know thatD．
A．PERV is found during Luhan Yang's experiments
B．PERV infecting rate has been reduced to 1‰now
C．the breakthrough is the result of a decade-long project
D．PERV is not a threat to same species in organ transplantation
34．Which of the following is TRUE？C
A．Explosive materials are used in experiments．
B．Experiments are carried out in 62locations in US．
C．Further research is still needed in Xenotransplantation．
D．Gene-editing method is used to remove harmful pig organs．
35．Which would be the best title for the passage？D
A．A big breakthrough in scientific field．
B．Viruses in pig cells are inactivated．
C．Viruses are defeated by scientists．
D．New hope in xenotransplantation．

分析 本文主要讲述了在器官移植方面需要克服的一个病毒问题，但是随着科学研究的进展，异种移植是有可能成为现实的．

解答 33．D 细节题．根据文章内容，the researchers described using gene-editing method to remove potentially harmful DNA sequences at 62locations，which are the remnants（留存之处） of a virus called PERV，from the pig genome…Pigs have been especially promising candidates due to their similar size and biological structure to humans由此可知，科学家已经使用了一种新的基因剪辑方式来移除病毒PERV，它对于同种类型的器官移植已不在是威胁，结合选项，故选D
34．C 推理题．根据文章内容，The team hopes eventually they can completely root out the risk that PERVs could cause disease in xenotransplantation by using modified pig cells to clone a line of pigs that would have their PERV inactivated．"We still have a long way to go，though．"Luhan added．研究团队希望以后能够用现代的猪身上的细胞来克隆出相应的使用在异种移植上．在这条路上，需要走的路还长，还有许多的工作需要做，结合选项，故选C
35．D 主旨题．根据文章内容，主要讲述了在器官移植方面需要克服的一个病毒问题，但是随着科学研究的进展，异种移植是有可能成为现实的．结合选项，故选D

点评 本文是一个科教类阅读理解，题目涉及多道细节理解题，做题时结合原文和题目有针对性的找出相关语句进行仔细分析，结合选项选出正确答案．推理判断题也是要在抓住关键句子的基础上合理的分析才能得出正确答案，切忌胡乱猜测，一定要做到有理有据．

练习册系列答案
相关题目
4．Beijing was under an"orange"smog alert on Feb.24，which marks the first time the second-highest warning level of a new system introduced last year_____．（　　）
A．has been raisedB．raisedC．has risenD．rose
8．The 20th century witnessed some of the most surprising achievements as far as the
field of science and  technology is concerned．Among_these，_the_Indians_account
_for_a_significant share_of_the_pie．
Srinivas Ramanujan （18871920）
Ramanujan's great mathematical findings were beginning to be appreciated from 1915 to 1919．But his ach ievements were to be fully understood much later，well after his death in 1920．For example，his work on highly composite numbers （高合成数） with a large number of factors started a whole new line of researches in the theory of such numbers．
Meghnad Saha （18931956）
Meghnad Saha belonged to an outstanding group of Indian scientists whose contributions revolutionised diverse branches of knowledge and earned global recognition．He introduced the teaching of Nuclear Physics in Calcutta University at a time when the world had not even witnessed the impact of Nuclear Energy．Together with S．N．Bose，he made the first English translation of Einstein's papers on r elativity．
C．V．Raman （18881970）
Raman's discovery that molecules scatter light is known as the Raman effect．It is used to study the internal structure of the molecules．Early in his life Raman carried out and published extensive research on acoustics （声学） and optics （光学）．He received the Nobel Prize for his wellknown Raman effect in 1930．
Dr Hargobind Khorana （ 1922）
Khorana shared the Nobel Prize in Medicine or Physiology in 1968 with Marshall W．Nirenberg and Robert W．Holley for cracking （破译） the genetic code．His researches have opened up a new branch called genetic engineering in science．In 1970 he became the Alfred Sloan Professor of Biology and Chemistry at the Massachusetts Institute of Technology where he continued his work．Apart from the Nobel Prize，Khorana has won many awards and honors for his achievement．
59．What does the underlined sentence mean in Paragraph 1？B
A．The Indians like to make pie．
B．Many most surprising ach ievements in science and technology are made by Indians．
C．The Indians receive all of most surprising achievements in science and technology．
D．The Indians play a significant role in sharin g the pie．
60．Whose contributions were NOT well received when he was alive？A
A．Srinivas Ramanujan's．
B．Meghnad Saha's．
C．C．V．Raman's．
D．Dr Hargobind Khorana's．
61．Dr Hargobind Khorana mainly researched intoC．
A．mathematics     
B．relativity  
C．genetic code 
D．optics
62．What would be the best title for this passage？D
A．Indian Scientific Achievements  
B．Indian Contributions to t he World
C．Famous Indian Universities in History
D．Famous Indian Scientists in the 20th Century．
5．We might not be alone in the universe．Actually，it may be confirmed as a very crowded place by new computer models developed to help identify habitable planets．
Estimates of places where life can exist have been based on the possibility of them having surface water．But software recently developed by the Aberdeen University allows researchers to identify planets with underground water kept liquid by heat from planets．
Water is fundamental for life and planets too close to the sun lose water to the atmosphere through evaporation．On the other hand，planets located in distant reaches from their star have their surface water locked away as ice．
Sean McMahon，who is carrying out the work，explained："Traditionally people have said that if a planet is in this Goldilocks zone-not too hot and not too cold-then it can have liquid water on its surface and be habitable．"
But this concept might change when considering that planets can receive two sources of heat-heat direct from the star and heat generated deep inside the planet．
It is easy to observe it in our own planet．As you go down through the crust  of the Earth，the temperature gets higher and higher．Even when the surface is frozen，water can exist below ground．
There could be immense quantities of water in fact-full of primitive life．
Professor John Parnell，also from Aberdeen University said："There is a significant habitat for microorganisms below the surface of the Earth，extending down several kilometers"．
"And some believe that the majority of life on Earth could even reside in this deep biosphere．"
So the Aberdeen team are developing models to predict which distant planets might harbor underground reservoirs of liquid water with the possibility of alien life．
28．What is considered as the symbol of life existence traditionally？D
A．Solid water on its surface．
B．Solid water below ground．
C．Liquid water below ground．
D．Liquid water on its surface．
29．Why did John Parnell mention the fact about Earth？B
A．To prove that there is majority of life on Earth．
B．To prove that life may also exist in other planets．
C．To prove that there is primitive life down through Earth．
D．To prove that there is a habitat for microorganisms below Earth．
30．What theory is the Aberdeen team's study based on？D
A．Planets can lose water through evaporation．
B．Planets can receive heat direct from the star．
C．Planets can have their surface water locked away as ice．
D．Planets can receive heat generated deep inside the planet．
31．What can we know about the computer models？A
A．They will help identify planets where there is life．
B．They will help researchers find Goldilocks zones．
C．They have helped find some significant discoveries．
D．They have already located some habitats for life．
12．Last night's meteor（流星） shower left many people in the community dissatisfied and demanding answers．According to Gabe Rothsclild，Emerald Valley's mayor，people gathered in the suburbs of the city，carrying heavy telescopes，expecting to watch the brightly burning meteors passing through the sky．What they found instead was a sky so brightened by the city's lights that it darkened the light of the meteors passing overhead．
"My family was so frustrated，"admitted town resident Duane Co sby，"We wanted to make this an unforgettable family outing，but it turned out to be a huge disappointments．"
     Astronomers---scientists who study stars and planets----have been complaining about this problem for decades．They say that light pollution prevents them from seeing objects in the sky that they could see quite easily in the past．They call on people and the government to take measures to fight against it．
     There is yet a population besides professional and amateur star observers that suffers even more from light pollution．This population consists of birds，bats frogs，snakes，etc．For example，outdoor lighting severely affects migrating（迁徙的）birds．According to the International Dark-Sky Association．"100 million birds a year throughout North America die in crashes with lighted buildings and towers．"
     Countless more animals casualties（伤亡）result from the use of artificial lighting．Clearly，people enjoy the benefits of lighting their evenings，but some scientists think it can be harmful for humans，too．They worry that exposure to light while sleeping can increase person's chances of getting cancer．
    Emerald Valley is only one community that is becoming aware of the negative effects of light pollution．For years，Flagstaff，Arizona，has enforced lighting regulations in its city in order to assist astronomers at the Lowell Observatory．Similar efforts have been made worldwide，and a movement is underway to remind us to turn off lights when we are not using them，so that other creatures can share the night．
32．It happened last night thatA
A．the city's lights affected the meteor watching      
B．the meteors flew past before being noticed               
C．the city light show attracted many people        
D．the meteor watching ended up a social outing
33．What the author concerned about according to Paragraph 4？D
A．Birds may take other migration paths            
B．Animal's living habits may change suddenly               
C．Varieties of animals will become sharply reduced         
D．Animals'survival is threatened by outdoor lighting
34．Lighting regulations in Flagstaff，Arizona are put into effect toB．
A．Lessen the chance of getting cancer          
B．create an ideal observation condition               
C．ensure citizens a good sleep at night         
D．enable all creatures to live in harmony
35．What message does the author most want to give us？C
A．Saving wildlife is saving ourselves          
B．Great efforts should be made to save energy               
C．Human activities should be environmentally friendly                 
D．New equipment should be introduced for space study．
2．假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下便条．便条中共有10处错误，每句中最多有两处．错误涉及一个单词的增加，删除或修改．
增加：在缺词处加一个漏词符号（∧），并在其下面写出该加的词．
删除；把多余的词用斜线（\）划掉．
修改：在错的词下划一横线，并在该词下面写出修改后的词．
注意：1．每处错误及修改均仅限一词；
2．只允许修改10处，多者（从第11处起）不计分．
Dear Bob，
I saw your note yesterday afternoon since I came back from school．You suggested that we go to concert this Friday evening．I'm sorry but I will be visit my uncle that day．He is going to Canada to do him PhD（哲学学位），and leave China this Sunday．I think I should say good-bye for him．
I'd really like to go to the concert．I knew the performances will continue until next weekend，so how do you think about going next Friday evening？Please let me know that we can go there together then．Give me a phone at 123000456．Thanks．
Li Hua．
9．"I will fight till forever!Whenever you knock me down，I will not stay on the ground．"This is"Never Say Never"，a song which is worthy of（61）being listened（listen） to．It（62）inspires（inspire） us to keep trying and never give up when we are in trouble，difficulty，or（63）failure（fail）．
But last week I saw a TV show，（64）where a scholar told people to learn to give up sometimes．He told the audience the following story．Once，he met a boy named John，who was not good at studying but skilled in cooking．So he suggested that the boy （65）（should） give （give） up the subjects that he wasn't good at and focus on his own（66）strength（strong）----cooking．The boy took his advice and devoted（67）himself to cooking．And now，the boy has become an outstanding cook----he has won a lot of awards in national cooking competitions．This story proves that giving up is not a bad thing．First，we should make a correct （68）judgement （judge）：What are our limitations？And what are our advantages？Then，by giving up something and sticking to something，we can find the access （69）to the goal we want to achieve．Therefore，what we need is to find the right place，（70）otherwise/or we will not be successful．
6．Everybody gets angry，but out-of-control anger isn't good for you or those around you．So 
here are five simple strategies to help you learn how to manage your anger：
•Relax．Breathe deeply，from your stomach．（36）F Repeat it to yourself and visualize a relaxing time and experience．
•Change the way you think．When you're angry，your thinking can get exaggerated （夸大的）．（37）A
 For instance，instead of telling yourself，"Oh，it's terrible!Everything's ruined，"tell yourself，"It's understadable that I'm upset about it，but it's not the end of the world．"
（38）•C Statements like"This never works．"or"You're always forgetting things．"will make you feel your anger is justified （情有可原的） and there's no way to solve the problem．
They might upset people who might be willing to work with you on a solution．
•Have a better communication．Angry people tend to jump to conclusions．If you are in a heated discussion，slow down．（39）B And take your time before answering．Instead of saying the first thing that comes into your head，think carefully about what you want to say．
•Use humor．Psychologists say that highly angry people tend to think"things ought to go my way!""Silly humor"can help you get a more balanced perspective．So，when you feel that anger coming the next time，picture yourself as a king or queen，walking around，admired by everybody，and getting your own way in every situation．The more detail you can get into your
imaginary scenes，the more likely it is to put a smile on your face．（40）G

A．Try replacing these thoughts with more reasonable ones．
B．Listen carefully to what the other person is saying．
C．Be careful with words like"never"or"always"．
D．Avoid using these strategies when you're in a tense situation．
E．Try changing the topics so your talks won't turn into arguments．
F．Then slowly repeat a calm word or phrase such as"take it easy"．
G．That will help you realize that the things you're angry about are really not very important．
7．Does Fame Drive You Crazy？
Although being famous might sound like a dream come true，today's stars，feeling like zoo animals，face pressures that few of us can imagine．They are at the center of much of the world's attention．Paparazzi （狗仔队） camp outside their homes，cameras ready．Tabloids（小报） publish thrilling stories about their personal lives．Just imagine not being able to do anything without being photographed or interrupted for a signature!
According to psychologist Christina Villarreal，celebrities-famous people-worry constantly about their public appearance．Eventually，they start to lose track of who they really are，seeing themselves the way their fans imagine them，not as the people they were before everyone knew their names．"Over time，"Villarreal says，"they feel separated and alone．"
The phenomenon of tracking celebrities has been around for ages．In the 4th century BC，painters followed Alexander the Great into battle，hoping to picture his victories for his admirers．When Charles Dickens visited America in the 19th century，his sold-out readings attracted thousands of fans，leading him to complain about his lack of privacy．Tabloids of the 1920s and 1930s ran articles about film-stars in much the same way that modern tabloids and websites do．
Being a public figure today，however，is a lot more difficult than it used to be．Superstars cannot move about without worrying about photographers with modern cameras．When they say something silly or do something ridiculous，there is always the Internet to spread the news in minutes and keep their"story"alive forever．
If fame is so troublesome，why aren't all celebrities running away from it？The answer is there are still ways to deal with it．Some stars stay calm by surrounding themselves with trusted friends and family or by escaping to remote places away from big cities．They focus not on how famous they are but on what they love to do or whatever made them famous in the first place．
Sometimes a few celebrities can get a little justice．Still，even stars who enjoy full justice often complain about how hard their lives are．They are tired of being famous already．

32．It can be learned from the passage that stars todayB．
A．are often misunderstood by the public
B．can no longer have their privacy protected
C．spend too much on their public appearance
D．care little about how they have come into fame
33．What is the main idea of Paragraph 3？B
A．Great heroes of the past were generally admired．
B．The problem faced by celebrities has a long history．
C．Well-known actors are usually targets of tabloids．
D．Works of popular writers often have a lot of readers．
34．What makes it much harder to be a celebrity today？A
A．Availability of modern media．
B．Inadequate social recognition．
C．Lack of favorable chances．
D．Huge population of fans．
35．What is the author's attitude toward modern celebrity？D
A．Disappointed．
B．Sceptical．
C．Disapproving．
D．Sympathetic．

违法和不良信息举报电话：027-86699610 举报邮箱：58377363@163.com

精英家教网