问答题Practice 2 Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope that transgenic techniques will allow more cost-effective and precise plants and animals with desirable characteristics that are not available using up to date breeding technology. Transgenic techniques allow genetic material to be transferred between completely unrelated organisms. In order for a transgenic technique to work, the genetic engineer must first construct a transgene, which is the gene to be introduced plus a control sequence. When making a transgene, scientists usually substitute the original promoter sequence with one that will be active in the correct tissues of the recipient plant or animal. The creation of transgenic animals is one of the most dramatic advances derived from recombinant DNA technology. A transgenic animal results from insertion of a foreign gene into an embryo. The foreign gene becomes a permanent part of the host animals’ genetic material. As the embryo develops, the foreign gene may be present in many cells of the body, including the germ cells of the testis or the ovary. If the transgenic animal is fertile, the inserted foreign gene (transgene) will be inherited by future progeny. Thus, a transgenic animal, once created, can persist into future generations. Transgenic animals are different from animals in which foreign cells or foreign organs have been engrafted. The progeny of engrafted animals do not inherit the experimental change. The progeny of transgenic animals do. The techniques for creating a transgenic animal include the following: 1) picking a foreign gene, 2) placing the foreign gene in a suitable form called a “construct” which guides the insertion of the foreign gene into the animal genome and encourages its expression, and 3) injecting the construct into a single fertilized egg or at the very early embryo stage of the host animal. Much genetic engineering goes into the choice of a foreign gene and building a construct. The construct must have promoters to turn on foreign gene expression at its new site within the host animal genome. By choosing a particular promoter and splicing it in front of the foreign gene, we can encourage expression of our transgene within a specific tissue. One of the most important applications of transgenic animals is the development of new animal models of human disease. Transgenic animals can serve as models for many malignant tumors. Mice have been the most frequent hosts for transgenic modification, other domestic animals have also been used. One idea has been to create transgenic cows which secrete important pharmaceutical substances in their milk. Other attempts are being made to express human interferon in the milk of sheep. A transgenic crop plant contains a gene or genes which have been artificially inserted instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: transgenic BT corn, for example, which produces its own insecticide, containing a gene from a bacterium. Plants containing transgenes are often called genetically modified or GM crops although in reality all crops have been genetically modified from their original wild state by domestication, selection and controlled breeding over long periods of time.
问答题
Practice 2 Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope that transgenic techniques will allow more cost-effective and precise plants and animals with desirable characteristics that are not available using up to date breeding technology. Transgenic techniques allow genetic material to be transferred between completely unrelated organisms. In order for a transgenic technique to work, the genetic engineer must first construct a transgene, which is the gene to be introduced plus a control sequence. When making a transgene, scientists usually substitute the original promoter sequence with one that will be active in the correct tissues of the recipient plant or animal. The creation of transgenic animals is one of the most dramatic advances derived from recombinant DNA technology. A transgenic animal results from insertion of a foreign gene into an embryo. The foreign gene becomes a permanent part of the host animals’ genetic material. As the embryo develops, the foreign gene may be present in many cells of the body, including the germ cells of the testis or the ovary. If the transgenic animal is fertile, the inserted foreign gene (transgene) will be inherited by future progeny. Thus, a transgenic animal, once created, can persist into future generations. Transgenic animals are different from animals in which foreign cells or foreign organs have been engrafted. The progeny of engrafted animals do not inherit the experimental change. The progeny of transgenic animals do. The techniques for creating a transgenic animal include the following: 1) picking a foreign gene, 2) placing the foreign gene in a suitable form called a “construct” which guides the insertion of the foreign gene into the animal genome and encourages its expression, and 3) injecting the construct into a single fertilized egg or at the very early embryo stage of the host animal. Much genetic engineering goes into the choice of a foreign gene and building a construct. The construct must have promoters to turn on foreign gene expression at its new site within the host animal genome. By choosing a particular promoter and splicing it in front of the foreign gene, we can encourage expression of our transgene within a specific tissue. One of the most important applications of transgenic animals is the development of new animal models of human disease. Transgenic animals can serve as models for many malignant tumors. Mice have been the most frequent hosts for transgenic modification, other domestic animals have also been used. One idea has been to create transgenic cows which secrete important pharmaceutical substances in their milk. Other attempts are being made to express human interferon in the milk of sheep. A transgenic crop plant contains a gene or genes which have been artificially inserted instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: transgenic BT corn, for example, which produces its own insecticide, containing a gene from a bacterium. Plants containing transgenes are often called genetically modified or GM crops although in reality all crops have been genetically modified from their original wild state by domestication, selection and controlled breeding over long periods of time.
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The idea that some groups of people may be more intelligent than others is one of those hypotheses that dare not speak its name.But Gregory Cochran is 1 to say it anyway.He is that 2 bird,a scientist who works independently 3 any institution.He helped popularize the idea that some diseases not 4 thought to have a bacterial cause were actually infections,which aroused much controversy when it was first suggested.5 he,however,might tremble at the 6 of what he is about to do.Together with another two scientists,he is publishing a paper which not only 7 that one group of humanity is more intelligent than the others,but explains the process that has brought this about.The group in 8 are a particular people originated from central Europe.The process is natural selection.This group generally do well in IQ test,9 12-15 points above the 10 value of 100,and have contributed 11 to the intellectual and cultural life of the West,as the 12 of their elites,including several world-renowned scientists,13.They also suffer more often than most people from a number of nasty genetic diseases,such as breast cancer.These facts,14,have previously been thought unrelated.The former has been 15 to social effects,such as a strong tradition of 16 education.The latter was seen as a（an）17 of genetic isolation.Dr.Cochran suggests that the intelligence and diseases are intimately 18.His argument is that the unusual history of these people has 19 them to unique evolutionary pressures that have resulted in this 20 state of affairs.13选？A.affirmB.witnessC.observeD.approve
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共用题干Adaptation of Living ThingsCertain animals and plants develop characteristics that help them cope with their environment better than others of their kind.This natural biological process is called adaptation.Among the superior characteristics developed through adaptation are those that may help in getting food or shelter,in providing protection,and in producing and protecting the young. That results in the evolution of more and more organisms（生物体）that are better fitted to their environments.Each living thing is adapted to its way of life in a general way,but each is adapted especially to its own distinct class.A plant,for example,depends upon its roots to fix itself firmly and toabsorb water and inorganic chemicals（无机物）.It depends upon its green leaves for using the sun's energy to make food from inorganic chemicals.These are general adaptations,common to most plants .In addition,there are special adaptations that only certain kinds of plants have.Many animals have adaptations that help them escape from their enemies.Some are hidden by their body color or shape,and many look like a leaf or a little branch.The coats of deer are colored to mix with the surroundings .Many animals .have the ability to remain completely still when an enemy is near.Organisms have a great variety of ways of adapting.They may adapt in their structure,func-tion,and genetics;in their development and production of the young;and in other respects.An organism may create its own environment, as do warm-blooded mammals（哺乳动物）,which have the ability to adjust body heat exactly to maintain their ideal temperature despite changing weather.Usually adaptations are an advantage,but sometimes an organism is so well adapted to a particular environment that if conditions change,it finds it difficult or impossible to readapt to the new conditions. Which of the following is NOT directly mentioned in the passage?A: A living thing may adapt in its structure.B: An organism may adapt in its function.C: A living creature may adapt in its genetic makeup.D: A living organism may adapt in its sleeping habit.
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 ovet 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. Chimpanzees 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-dlined because they are so resistant.5 By sequencing the chimp genome and pinpointing（找到）the place where the chimpanzee 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 alteration（改变）of the human genetic sequence. The recently completed human genome sequencing project has shown that such an effort is now well within our reach.Paragraph 2______A: Reasons for HIV ResistanceB: Implications of Chimpanzee Extinction for HumansC: Effective AIDS TreatmentD: Genetic Similarities Between Chimps and HumansE: Chimps'Resistance to HIVF: Genetic Differences Between Chimps and Humans
共用题干The Gene IndustryMajor companies are already in pursuit of commercial applications of the new biology.They dream of placing enzymes（酶）in the automobile to monitor exhausts and send data on pollution to a microprocessor（微处理机）that will then adjust the engine. They speak of what the New YorkTimes calls “metal-hungry microbes（渴望吃金属的微生物）that might be used to mine valuable trace metals from ocean water”.They have already demanded and won the right to patent new lifeforms.Nervous critics,including many scientists,wony that there is corporate,national,intema- tional , and inter-scientific rivalry in the entire biotechnological（生物工艺学）field. They create images not of oii spills,but of“microbe spills”that could spread disease and destroy entire pop- ulations. The creation and accidental release of extremely poisonous microbes,however,is only one cause for alarm.Completely rational and respectable scientists are talking about possibilities that stagger the imagination.Should we breed people with cow-like stomachs so they can digest grass and hay,thereby relieving the food problem by modifying us to eat lower down on the food chain?Should we biologi- cally alter workers to fit the job requirement,for example,creating pilots with faster reaction times or assembly-line workers designed to do our monotonous work for us?Should we attempt to eliminate“inferior”people and breed a“super-race”?(Hitler tried this,but without the genetic weaponry that may soon issue from our laboratories.)Should we produce soldiers to do our fighting? Should we use genetic forecasting to pre-eliminate“unfit”babies?Should we grow reserve organs for ourselves,each of us having,as it were,a“savings bank”full of spare kidneys,livers or hands?Wild as these notions may sound,every one has its advocates(and opposers)in the scientific community as well as its striking commercial application.As two critics of genetic engineering,Jeremy Rifkin and Ted Howard,state in their book Who Should Play God?“Broad scale genetic engineering will probably be introduced to America much the same way as assembly lines,automobiles,vaccines,computers and all the other technologies.As each new genetic advance becomes commercially practical,a new consumer need will be exploited and a market for the new technology will be created.” Which of the following notions is NOT mentioned?A: Developing a“savings bank”of one's organs.B: Breeding soldiers for a war.C: Producing people with cow-like stomachs.D: Using genetic forecasting to cure diseases.
共用题干The Gene IndustryMajor companies are already in pursuit of commercial applications of the new biology.They dream of placing enzymes（酶）in the automobile to monitor exhausts and send data on pollution to a microprocessor（微处理机）that will then adjust the engine. They speak of what the New YorkTimes calls “metal-hungry microbes（渴望吃金属的微生物）that might be used to mine valuable trace metals from ocean water”.They have already demanded and won the right to patent new lifeforms.Nervous critics,including many scientists,wony that there is corporate,national,intema- tional , and inter-scientific rivalry in the entire biotechnological（生物工艺学）field. They create images not of oii spills,but of“microbe spills”that could spread disease and destroy entire pop- ulations. The creation and accidental release of extremely poisonous microbes,however,is only one cause for alarm.Completely rational and respectable scientists are talking about possibilities that stagger the imagination.Should we breed people with cow-like stomachs so they can digest grass and hay,thereby relieving the food problem by modifying us to eat lower down on the food chain?Should we biologi- cally alter workers to fit the job requirement,for example,creating pilots with faster reaction times or assembly-line workers designed to do our monotonous work for us?Should we attempt to eliminate“inferior”people and breed a“super-race”?(Hitler tried this,but without the genetic weaponry that may soon issue from our laboratories.)Should we produce soldiers to do our fighting? Should we use genetic forecasting to pre-eliminate“unfit”babies?Should we grow reserve organs for ourselves,each of us having,as it were,a“savings bank”full of spare kidneys,livers or hands?Wild as these notions may sound,every one has its advocates(and opposers)in the scientific community as well as its striking commercial application.As two critics of genetic engineering,Jeremy Rifkin and Ted Howard,state in their book Who Should Play God?“Broad scale genetic engineering will probably be introduced to America much the same way as assembly lines,automobiles,vaccines,computers and all the other technologies.As each new genetic advance becomes commercially practical,a new consumer need will be exploited and a market for the new technology will be created.” What dose Jeremy Rifkin and Ted Howard's statement imply?A: The commercial applications of genetic engineering are inevitable.B: America will depend on other countries for biological progress.C: Americans are proud of their computers,automobiles and genetic technologies.D: The potential application of each new genetic advance should be controlled.
共用题干第三篇Citizen ScientistsUnderstanding how nature responds to climate change will require monitoring key life cycle events一 flowering,the appearance of leaves and the first frog calls of the spring一all around the world.But ecologists can't be everywhere so they're turning to non-scientists,sometimes called citizen scientists,for help.Climate scientists are not present everywhere.Because there are so many places in the world and not enough scientists to observe all of them,they're asking for your help in observing signs of climate change across the world.The citizen scientist movement encourages ordinary people to observe a very specificresearch interest一birds,trees,flowers budding,etc.and send their observations to a giant database to be observed by professional scientists.This helps a small number of scientists track a large amount of data that they would never be able to gather on their own.Much like citizen journalists helping large publications cover a hyper-local beat,citizen scientists are ready for the conditions where they live in.All that's needed to become one is a few minutes each day or each week to gather data and send them in.A group of scientists and educators launched an organization last year called the National Phenology 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 alike to collect data about plant flowering and leafing eveiy year.The program,called Project BudBurst,collects life cycle data on a variety of common plants from across the United States.People participating in the project一which is open to every- one一record their observations on the Project BudBurst website."People don't have to be plant experts一they just have to look around and see what's in their neighbor- hood,"says Jennifer Schwartz,an education consultant with the project."As we collect these data,we'll be able to make an estimate of how plants and communities of plants and animals will respond as the climatechanges."What is the final purpose of Project BudBurst?A:To study when plants will have their first buds.B:To find out the types of plants in the neighborhood.C:To collect life cycle data on a variety of common plants from across the United States.D:To investigate how plants and animals will respond as the climate changes.
共用题干第三篇The Gene IndustryMajor companies are already in pursuit of commercial applications of the new biology.They dream of placing enzymes in the automobile to monitor exhaust and send data on pollution to a microprocessor that will then adjust the engine. They speak of what the New York Times calls "metal-hungry microbes that might be used to mine valuable trace metal from ocean water".They have already demanded and won the right to patent new life forms.Nervous critics, including many scientists, worry that there is corporate, national, international,and inter-scientific rivalry in the entire biotechnological field.They create images not of oil spills,but of"microbe spills"that could spread disease and destroy entire populations.The creation and accidental release of extremely poisonous microbes,however,is only one cause for alarm.Completely rational and respectable scientists are talking about possibilities that stagger the imagination.Should we breed people with cow一with stomachs so they can digest grass and hay,thereby relieving the food problem by modifying us to eat lower down on the food chain?Should we biologically alter workers to fit the job requirement,for example,creating pilots with faster reaction times or assembly-line workers designed to do our monotonous work for us?Should we attempt to eliminate "inferior" people and breed a"super-race"?(Hitler tried this,but without the genetic weaponry that may soon issue from our laboratories.)Should we produce soldiers to do our fighting?Should we use genetic forecasting to pre-eliminate"unfit"babies?Should we grow reserve organs for ourselves, each of us having,as it were,a"savings bank"full of spare kidney,livers,or hands?Wild as these notions may sound,every one has its advocates(and opposers)in the scientific community as well as its striking commercial application.As two critics of genetic engineering, Jeremy Rifkin and Ted Howard,state in their book Who Should Play God?,"Broad scale genetic engineering will probably be introduced to America much the same way as assembly lines,automobiles,vaccines,computers and all the other technologies.As each new genetic advance becomes commercially practical,a new consumer need will be exploited and a market for the new technology will be created."According to the passage,Hitler attempted to________.A:change the pilots biologically to win the warB:develop genetic farming for food supplyC:kill the people he thought of as inferiorD:encourage the development of genetic weapons for the war
共用题干第三篇The Gene IndustryMajor companies are already in pursuit of commercial applications of the new biology.They dream of placing enzymes in the automobile to monitor exhaust and send data on pollution to a microprocessor that will then adjust the engine. They speak of what the New York Times calls "metal-hungry microbes that might be used to mine valuable trace metal from ocean water".They have already demanded and won the right to patent new life forms.Nervous critics, including many scientists, worry that there is corporate, national, international,and inter-scientific rivalry in the entire biotechnological field.They create images not of oil spills,but of"microbe spills"that could spread disease and destroy entire populations.The creation and accidental release of extremely poisonous microbes,however,is only one cause for alarm.Completely rational and respectable scientists are talking about possibilities that stagger the imagination.Should we breed people with cow一with stomachs so they can digest grass and hay,thereby relieving the food problem by modifying us to eat lower down on the food chain?Should we biologically alter workers to fit the job requirement,for example,creating pilots with faster reaction times or assembly-line workers designed to do our monotonous work for us?Should we attempt to eliminate "inferior" people and breed a"super-race"?(Hitler tried this,but without the genetic weaponry that may soon issue from our laboratories.)Should we produce soldiers to do our fighting?Should we use genetic forecasting to pre-eliminate"unfit"babies?Should we grow reserve organs for ourselves, each of us having,as it were,a"savings bank"full of spare kidney,livers,or hands?Wild as these notions may sound,every one has its advocates(and opposers)in the scientific community as well as its striking commercial application.As two critics of genetic engineering, Jeremy Rifkin and Ted Howard,state in their book Who Should Play God?,"Broad scale genetic engineering will probably be introduced to America much the same way as assembly lines,automobiles,vaccines,computers and all the other technologies.As each new genetic advance becomes commercially practical,a new consumer need will be exploited and a market for the new technology will be created."According to the passage,the exhaust from a car engine could probably be checked by________.A:using metal-hungry microbesB:making use of enzymesC:adjusting the engineD:patenting new life forms
共用题干第三篇The Gene IndustryMajor companies are already in pursuit of commercial applications of the new biology.They dream of placing enzymes in the automobile to monitor exhaust and send data on pollution to a microprocessor that will then adjust the engine. They speak of what the New York Times calls "metal-hungry microbes that might be used to mine valuable trace metal from ocean water".They have already demanded and won the right to patent new life forms.Nervous critics, including many scientists, worry that there is corporate, national, international,and inter-scientific rivalry in the entire biotechnological field.They create images not of oil spills,but of"microbe spills"that could spread disease and destroy entire populations.The creation and accidental release of extremely poisonous microbes,however,is only one cause for alarm.Completely rational and respectable scientists are talking about possibilities that stagger the imagination.Should we breed people with cow一with stomachs so they can digest grass and hay,thereby relieving the food problem by modifying us to eat lower down on the food chain?Should we biologically alter workers to fit the job requirement,for example,creating pilots with faster reaction times or assembly-line workers designed to do our monotonous work for us?Should we attempt to eliminate "inferior" people and breed a"super-race"?(Hitler tried this,but without the genetic weaponry that may soon issue from our laboratories.)Should we produce soldiers to do our fighting?Should we use genetic forecasting to pre-eliminate"unfit"babies?Should we grow reserve organs for ourselves, each of us having,as it were,a"savings bank"full of spare kidney,livers,or hands?Wild as these notions may sound,every one has its advocates(and opposers)in the scientific community as well as its striking commercial application.As two critics of genetic engineering, Jeremy Rifkin and Ted Howard,state in their book Who Should Play God?,"Broad scale genetic engineering will probably be introduced to America much the same way as assembly lines,automobiles,vaccines,computers and all the other technologies.As each new genetic advance becomes commercially practical,a new consumer need will be exploited and a market for the new technology will be created."According to the passage,which of the following would worry the critics the most?A:The unanticipated explosion of population.B:The creation of biological solar cells.C:The accidental spill of oil.D:The unexpected release of destructive microbes.
共用题干第三篇Genetic EngineeringGenetic engineering began when the DNA molecule（分子）,the most basic unit of life, was first described in 1953 by James Watson and Francis Crick.An understanding of DNA led to the altering of normal cell reproduction.Experiments with altering human cells began in 1970.In one of the first experiments,patients were injected with a virus that would produce a life-saving enzyme,but their bodies would not accept it.In 1980 patients with a rare but fatal blood disease were injected with a purified gene that was cloned through DNA technology.Another failure.Genetic engineering got a legal boost（激励）in 1980. The U. S. Supreme Court said that a patent could be granted on a genetically engineered " oil-eating" bacterium（细菌）.This bacterium would help clean up oil spills.The ruling encouraged companies to invent new life forms,and three important medical products were quickly developed.1.Human interferon（干扰素）一a possible solution to some cancers and viral diseases. A newly engineered bacterium produced human interferon as a by-product. This new product reduced the cost of interferon.2. Human growth hormone（荷尔蒙）一for children whose bodies do not grow to normal height. An expensive growth hormone was previously produced from human cadavers,but by changing the genetic make-up of the single-cell bacterium E.coli,and affordable growth hormone could be produced.3. Human insulin (胰岛素）一for the treatment of diabetes. People with diabetes used to rely on a beef-or-pork-basedproduct until 1982.Now insulin can be manufactured by genetically altered bacteria.Advances in genetic engineering have continued,though they constantly must be weighed against the safety of procedures.There is clearly much more to discover.In this passage,the three genetically engineered medical products are presented__________.A:as a processB:in a simple listC:from earliest to latestD:as a story
共用题干第三篇Genetic EngineeringGenetic engineering began when the DNA molecule（分子）,the most basic unit of life, was first described in 1953 by James Watson and Francis Crick.An understanding of DNA led to the altering of normal cell reproduction.Experiments with altering human cells began in 1970.In one of the first experiments,patients were injected with a virus that would produce a life-saving enzyme,but their bodies would not accept it.In 1980 patients with a rare but fatal blood disease were injected with a purified gene that was cloned through DNA technology.Another failure.Genetic engineering got a legal boost（激励）in 1980. The U. S. Supreme Court said that a patent could be granted on a genetically engineered " oil-eating" bacterium（细菌）.This bacterium would help clean up oil spills.The ruling encouraged companies to invent new life forms,and three important medical products were quickly developed.1.Human interferon（干扰素）一a possible solution to some cancers and viral diseases. A newly engineered bacterium produced human interferon as a by-product. This new product reduced the cost of interferon.2. Human growth hormone（荷尔蒙）一for children whose bodies do not grow to normal height. An expensive growth hormone was previously produced from human cadavers,but by changing the genetic make-up of the single-cell bacterium E.coli,and affordable growth hormone could be produced.3. Human insulin (胰岛素）一for the treatment of diabetes. People with diabetes used to rely on a beef-or-pork-basedproduct until 1982.Now insulin can be manufactured by genetically altered bacteria.Advances in genetic engineering have continued,though they constantly must be weighed against the safety of procedures.There is clearly much more to discover.Genetic engineering may be defined as_________.A:the altering of normal cell reproductionB:a branch of applied chemistryC:a procedure that holds little promiseD:a study on life-saving enzymes
The most suitable mode of transport for the goods which have to be moved by a vessel from a port in one country to a port in another country and then by rail to a second port city in the second country is （）.A、mini-bridgeB、sea trainC、sea/airD、piggyback
Users can define policy to control traffic flow between which two components？（）A、from a zone to the device itselfB、from a zone to the same zoneC、from a zone to a different zoneD、from one interface to another interface
Which command will migrate a filesystem from one volume group to another？（）A、cpfsB、cplvC、mkfscopyD、migratepv
问答题Practice 3 Dolly was no ordinary lamb. She was cloned from a single mammary cell of an adult ewe, overturning long- held scientific dogma that had declared such a thing biologically impossible. Her birth set off a race in laboratories around the world to duplicate the breakthrough and raised the specter of human cloning. A decade later, scientists are starting to come to grips with just how different Dolly was. Dozens of animals have been cloned since that first little lamb and it’s becoming increasingly clear that they are all, in one way or another, defective. It’s tempting to think of clones as perfect carbon copies of the original—down to every hair and quirk of temperament. It turns out, though, that there are various degrees of genetic replication. Not only are clones separated from the original template by time—-in Dolly’s case, six years—but they are also the product of an unnatural molecular mechanism that turns out not to be very good at making identical copies. But scientists see a role for cloning in treating human diseases—and perhaps someday conquering some of man’s most intractable conditions. It may be another 10 years or more before the approach yields anything safe and reliable enough to be used in real patients, and there is no guarantee that it will ever be successful. But nobody thought Dolly was possible until she made history that warm July night 10 years ago.
问答题Directions:In this section, there is one passage followed by 5 questions. Read the passage carefully, then answer the questions in as few words as possible (not more than 10 words). Remember to write the answers on the Answer Sheet. Questions 1-5 are based on the following passage. Many people today are worried about bird flu. They are afraid that it will pass from birds to humans and that thousands of people will die in a pandemic. In 1918 a flu virus killed about 50 million people around the world. The virus was called Spanish influenza (or Spanish flu, for short) because Spanish newspapers first described the disease. Now, after nine years of work, scientists in an American laboratory in Atlanta, Georgia, have produced a copy of the Spanish flu virus. They are also going to publish the genetic sequence of the virus on the Internet and some experts are afraid that other laboratories could copy the virus. Scientists have copied the virus because they want to understand why the 1918 Spanish flu pandemic killed so many people. In a report in the journal Science, Dr. Jeffery Taubenberger and a team of scientists in the USA show that the copied virus is extremely powerful. The scientists injected the virus into mice and the mice began to lose weight very quickly. They lost 13% of their weight in two days and all of the mice died within six days. “I didn’t expect it to be as lethal as it was,”Dr. Terrence Tumpey, one of the scientists in the team, told the journal Nature. In another experiment, they injected more mice with a normal type of flu. The mice lost weight at first but then they got better and did not die. The experiments showed that the mice with the Spanish flu virus had 39,000 times more flu virus in their bodies than the second group of mice. The scientists who copied the virus say their work has already provided important information about the virus and helps to explain why it is so lethal. But other experts are worried that the virus could escape from the laboratory. “Some people will think that they have really created a biological weapon,” said Professor Ronald Atlas of the University of Louisville in Kentucky. “I am even more worried now than I was before about the possibility of a flu pandemic. The 1918 flu pandemic started with bird flu and that might happen again today with Asian bird flu.” Some scientists are worried about the publication of the genetic sequence on the Internet. They are afraid that biologists could copy the virus using the information on the Internet. This could be very dangerous. It took a long time to copy the virus. Scientists used material taken from the lungs of people who died from the flu virus in 1918. In a second report in Nature, Taubenberger and his colleagues analyzed the genetic make-up of the virus. They were surprised to find that it was completely different from all the normal human flu viruses. This probably means that Spanish flu jumped from birds to humans and did not mix with a human virus first. This is very worrying for scientists because in the past everyone believed that a pandemic was only possible if a bird flu virus mixed with a human flu virus. Taubenberger says it is very important to know what changes in the virus caused the 1918 Spanish flu virus. This will help scientists to work out which viruses might cause a pandemic. The H5N1 bird flu in Asia is already changing and it could infect humans, he said. Viruses have escaped from high-security labs before. The SARS virus escaped at least twice, once in Taiwan and once in Singapore. But some scientists believe a pandemic will not happen even if the virus escapes, because most people are naturally immune and there are now a lot of drugs which protect people from flu. Questions: 1．When was the Spanish flu pandemic? 2．How many people died in the Spanish flu pandemic? 3．Where did the scientists produce a copy of the Spanish flu virus? 4．How quickly did the laboratory mice die? 5．What is H5N1?
问答题Animal rights are a controversial topic right now. Actually, the debate is focused mainly on animal testing. The following are opinions from both sides. Read the excerpts carefully and write your response in about 300 words, in which you should: 1. summarize briefly the opinions from both sides, and then 2. give your comment. Marks will be awarded for content relevance, content sufficiency, organization and language quality. Failure to follow the above instructions may result in a loss of marks. Animals are used for research in a variety of settings, including tests to determine the safety of drugs, cosmetics and other substances. Whether or not humans should use animals for testing purposes, however, is a controversial subject. Dr. Bob Miller, a medical researcher from Michigan State University, states that one of the primary advantages of animal testing is that it allows researchers to develop new medications and treatments, advancing the field of medicine and enhancing the health of society. For instance, many drugs used to treat or prevent cancer, HIV, diabetes, infections and other medical maladies have resulted from tests performed on animals. Moreover, animal testing enables scientists and researchers to test the safety of medications and other substances with which humans have regular contact. Drugs, for instance, may pose significant risks to humans, so testing them on animals fast gives researchers a chance to determine drugs’ safety before human trials are performed. While scientists are cognizant of the differences between humans and animals, the similarities are considered significant enough to produce relevant, useful data that they can then apply to humans. Thus, animal testing reduces harm to humans and saves lives. However, Prof. Abhay Shina, a leading critic of animal testing, points out that the major disadvantage to animal testing is that a significant number of animals are harmed or die as a result of experiments and testing. Unfortunately, many of the substances used on animal subjects never receive approval for human use or consumption. Humans receive no direct benefits as a result of the deaths of these animals. He also argues that animals are dissimilar enough from humans to make the results of animal tests unreliable. A related criticism is that testing induces stress in the animals, meaning that the subjects do not react to experimental substances in the same way that they might in more natural circumstances, making the results of experiments less valid. Using animals as research subjects is also expensive, because the animals require food, shelter, care and treatment in addition to the costs of experimental substances. Long-term or multi-phase tests can increase the costs of the practice as well. The actual price paid for the animals is also worth consideration; there are companies that breed and sell animals specifically for testing purposes.
单选题EXHIBIT, Emp Table Exhibit A Exhibit B Examine the data from the EMP table. Evaluate this SQL statement: SELECT * FROM emp WHERE emp _ id = 3); WHERE commission = (SELECT commission FROM emp What is the result when the query is executed?（）A Exhibit AB Exhibit BC The query returns no rowsD The query fails because the outer query is retrieving more than one columnE The query fails because both the inner and outer queries are retrieving data from the same table.
问答题The Truth about Genetically Modified Food At almost every public lecture I give, someone asks me my opinion on genetic modification—whatever be the topic of the lecture. Genetic modification (GM) has the power to save lives through its use in medicine, such as the production of insulin for diabetics or the treatment of genetic disorders. The current outcry comes when it is used to produce food. Some of these public concerns reflect real problems, but others are fuelled by misinformation and overdramatisation. There is nothing new about crop modification; plant breeders have been doing it since agriculture began. The wonderful range of apples or potatoes we now enjoy is the result of crossing different varieties. Cabbages, Brussels sprouts, cauliflower, kohlrabi, kale and broccoli all originated from one botanical species. Modern molecular biology has enabled us to go much further. We can now isolate the gene for a particular characteristic of an organism and transfer it to another species. It is this practice of transforming a plant with alien genes—perhaps from an animal or bacterium—that is causing all the controversy. There are three main concerns. Scientists can now take a gene for resistance to a particular herbicide and transfer it to a crop: when these plants are sprayed with weed-killer, the weeds are destroyed while the crop is unharmed. A prime concern is the harmful effect this could have on the biodiversity of farmland, where so many insects, birds and other animals depend upon “weed” species. Another fear is that alien genes from a GM plant could escape into a wild population of a related species. Since plants are fertilized by pollen that is carried through their, often for great distances, this is entirely possible. A wild species modified in this way with pesticide resistance could become a “super-weed”, while a species that becomes unnaturally resistant to animals that feed on it could disrupt the food chain. The third worry concerns a proposal to produce seeds for cereals that cannot germinate to produce next year’s seeds. This “terminator technology” would be of obvious advantage to seed companies, since farms would be forced to buy new weed annually. But the same technology could be devastating to some farmers in the developing world who depend upon saving some seeds for next year’s crop. Fortunately this technology is not yet in use and there has been strong pressure to abandon it. I would not hesitate to eat a GM vegetable—it is most unlikely that the current modifications are harmful to the consumer, despite what we read in the press. However, the introduction of animal genes into food plants presents considerable ethical difficulties to vegetarinsarians and member of religious that forbid the eating of certain animals. This is one of the reasons people are demanding that tall genetically modified food products be clearly labeled. The public have a fight to know what they are eating and a fight to choose. I believe that in my own nation GM is well regulated, but this cannot be said for some other countries. One of the problems is that at the moment this technology is commercially motivated. Because the compositions developing GM food want to introduce it as quickly as possible, in my opinion, it is being rushed into without adequate research or precautions. Genetic’ modification is here to stay, and there is no doubt it will save lives. But ,like so many other scientific discoveries, such as splitting the atom, it can be seriously misused. Instead of condemning the technique, we, should ensure it is used wisely. We need to evaluate each application carefully, from environmental and ethical standpoints, and we must urge governments and companies to use it for good rather than for greed.
单选题The ladder shall（）.Abe secured in a position so that it rests firmly against the ship's side from which the discharge operations are carried outBhave at least two replacement steps which are secured in position by a method different from that used in the original constructionChave battens made of hardwood，or other material of equivalent properties，in one piece and not less than 1.80metres long provided at such intervals as will prevent the pilot ladder from twistingDhave steps made of softwood，or other material of equivalent properties，made in one piece free of knots，having an efficient slip surface