单选题PPL scientists will try to solve their problem by ______.A removing the sugar molecule on the surface of pig cells.B distinguishing human tissues form those of pigs.C using the sugar-free nucleus in cloning a pig.D taking out the sugar genes from the cell of a pig.

考题 Mr.Johnson keeps fit by eating less fat and sugar and ______ more exercise. A.takesB.takeC.to takeD.taking

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考题 The common form. of sugar is derived () two plants: the sugar cane and the sugar beet. A. fromB. ofC. aboutD. on

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考题 If cloned animals could be used as organ donors, ().A、people don’t have to worry about cloning twins for transplantsB、raising animals such as pigs can help solve the problemC、the human body attacks and destroys tissue from other speciesD、it may be more efficient to produce such animals by cloning than by cur

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考题 Why do some people support cloning?() A.It can help those infertile couplesB.It may revolutionize organ transplantationC.It could save seriously endangered speciesD.It may solve the problem of starvation

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考题 No Sweet Talk About SugarSugar's proponents call it quick energy, opponents say it's empty calories (卡路里) 。 But to the average person, who consumes a quarter of a pound of it each day, sugar is mostly an irresistibly good taste.In fact, people seem to have an innate "sweet tooth."Human societies have long equated sweetness with goodness - sweet mystery of life, sweet smell of success, sweetheart - and that enhances (增强;提高) the attraction.But in recent years, sugar has also been singled out as a potential enemy of the healthy life.Cited for such evils as distracting youngsters from more nutritious (营养的) foodstuffs, enhancing obesity (肥胖), ruining teeth and causing diabetes(糖尿病), it has become the most maligned (恶毒的) of the main components of our diet.Sugar, like starch, is a carbohydrate (碳水化合物).Its many types include sucrose (table sugar refined from sugarcane or beets), lactose (milk sugar), fructose (fruit sugar), glucose (blood sugar), dextrose (右旋糖), maltose(麦芽糖) and galactose (半乳糖).Seventy percent of the sugar in the labels on all the packaged products in your pantry (食品室) and see how many list sugar (or corn syrup) as a main ingredient (成分) 。Early this century, the average North American consumed about 76 pounds of refined sugar a year, but starches formed two thirds of his dietary carbohydrates.Today, per-capita refined sugar consumption hovers around 95 pounds, and all types of sugar represent more than half the carbohydrate calories.But in relying on sucrose-sweetened processed foods as a main carbohydrate source, we may miss the essential nutrients - fiber, vitamins and minerals - found in other carbohydrate foods like fruits, vegetables and breads.The body has no physiological need for sucrose that cannot be satisfied by other, more nutritious foods.The body can convert starches to sugar, or use the sugar in fruits and vegetables for energy.In fact, nutrition experts say that even the purported (传说的) need for sugar as quick energy is a myth except in a few rare situations, such as a diabetic in insulin shock.During exercise, the body calls upon its reserve of glycogen (肝糖) (and, if that runs low, fatty acids from the breakdown of triglycerides) to supply the muscles with needed energy.If you eat sugar before exercising, your body simply stores it.As for sugar's reputed adverse (不利的) health effects, the following can be said on the basis of available evidence:Obesity, Sugar supplies four calories per gram - about the same as protein and less half that of fat.Excess caloric intake, not sugar, causes obesity.But since calories can be highly concentrated in sugar-sweetened foods, you may eat many more calories than you need of such foods before you feel full or even realize how much you consumed.Tooth decay.Sugar definitely promotes the development of dental caries.Bacteria in the mouth digest (消化) the sugar on tooth surfaces, and produce acid which eats away the enamel (珐琅).It is the time sugar remains on the teeth, rather than the amount eaten, that makes the difference.To reduce the risk of decay, dentists recommend rinsing your mouth or brushing you teeth after consuming anything sweet, and avoiding sweets between meals.Diabetes.In diabetes, the pancreas (胰腺) fails to produce enough insulin to clear the blood of excess glucose.Thus, diabetics must curb their intake of sweets lest their blood-sugar levels rise dangerously high.But the important factor in diabetes is controlling body weight.Heart Disease.The theory that sugar is an important factor in heart disease does not have wide support among experts, who say that fats and cholesterol (胆固醇) are the more likely culprits (罪魁祸首).Some people have a tendency to develop high blood levels of fatty substances called triglycerides, which may promote atherosclerosis (动脉硬化).They are often advised to reduce their sugar intake, but losing weight is more important.Diets free of sucrose can lower abnormally high triglyceride levels, but they have been found to have little or no effect on triglyceride levels that are acceptable in the first place.1、What does the word "innate" mean?()A、born withB、implantedC、badD、healthy2、Which of the following statements is NOT true?()A、There are many types of sugar such as sucrose, lactose, fructose, etc.B、Sugar can cause many health problems such as obesity, tooth decay and diabetes.C、Sugar is not nutritious because it doesn't contain fiber, vitamin and mineral.D、Sugar is physiologically needed by the body and can not be substituted by other substance.3、"Curb their intake of sweets" can also be referred to as()their intake of sweets.A、increaseB、decreaseC、limitD、take4、Based on the ideas presented in the passage we can conclude that ().A、there is not available evidence to show sugar's bad effectsB、if you eat a lot of sweet food, you may suffer from obesity, because such food contains a lot of caloriesC、to limit sugar intake is the most important thing for the atherosclerosis patientD、most experts believe that sugar can cause heart disease5、From the passage, we know().A、sugar eats away the enamel, thus causing tooth decayB、the cause for diabetes is the excessive intake of sugarC、fats and cholesterol have nothing to do with heart diseaseD、high level triglycerides may increase the chances of atherosclerosis

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考题 A group of scientists are conducting a(_______)into the feasibility of cloning human beings. A. entranceB.researchC.inquiryD.investigation

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考题 Which of the following best represents Mr. Westhusin’s attitude toward cloning?［A］ Animal cloning is a stupid attempt.［B］ Human cloning is not yet close to getting it worked out.［C］ Cloning is too inefficient and should be stopped.［D］ Animals cloning yes, and human cloning at least not now.

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考题 We may conclude from the text that _____.［A］ human cloning will not succeed unless the technique is more efficient［B］ scientists are optimistic about cloning technique［C］ many people are against the idea of human cloning［D］ cloned animals are more favored by owners even if they are weaker

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考题共用题干 The Tough Grass That Sweetens Our LivesSugar cane was once a wild grass that grew in New Guinea and was used by local people for roofing their houses and fencing their gardens. Gradually a different variety evolved which contained sucrose（蔗糖）and was chewed on for its sweet taste. Over time,sugar cane became a highly valuable commercial plant,grownthroughout the world. _________(46)Sugar became a vital ingredient in all kinds of things ,from confectionery（糖果点心）to medicine , and, as the demand for sugar grew ,the industry became larger and more profitable.__________(47)Many crops withered（枯萎）and died,despite growers' attempts to save them ,and there were fears that the health of the plant would continue to deteriorate.In the 1960s ,scientists working in Barbados looked for ways to make the commercial species stronger and more able to resist disease. They experimented with breeding programmes,mixing genes from the wild species of sugar cane,which tends to be tougher, with genes from the more delicate,commercial type. ___________(48)This sugar cane is not yet ready to be sold commercially,but when this happens,it is expected to he incredibly profitable for the industry.____________ (49)Brazil , which produces one quarter of the world's sugar, has coordinated an intema- tional project under Professor Paulo Arrudo of the Universidade Estaudual de Campinas in Sao Paulo. Teams of experts have worked with him to discover more about which parts of the genetic structure of the plant are important for the production of sugar and its overall health.Despite all the research ,however, we still do not fully understand how the genes function in sugar cane.___________(50)This gene is particularly exciting because it makes the plant resistant to rust,a disease which probably originated in India,but is now capable of infecting sugar cane across the world.Scientists believe they will eventually be able to grow a plant which cannot be destroyed by rust.________（49）A:Since the 1960s,scientists have been analysing the mysteries of the sugar cane'S genetic code.B:Unfortunately,however,the plant started to become weaker and more prone to disease.C:The majority of the world'5 sugar now comes firm this particular commercial species.D:One major gene has been identified by Dr Angelique D'Hont and her team in Montpeller,France.E:Eventually,a commercial plant was developed which was 5 percent sweeter than before,but also much stronger and less likely to die from disease.F: Sugar cane is now much more vigorous and the supply of sugar is therefore more guaranteed.

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考题共用题干 Cloning（克隆）:Future Perlect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves（牛犊）using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clone a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative,In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U. S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Journal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded（轰炸）with newspaper articles, television shows and films, as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cloning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like,But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool, answer the pro-cloners（赞成克隆的人）.Within ten years scientists wil!probably have_______.A:the nucleus of a cellB:cloned human beingsC:a human being in two yearsD:a law to ban human cloningE:a report on human cloningF:heavy media coverage

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考题共用题干 Cloning（克隆）:Future Perlect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves（牛犊）using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clone a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative,In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U. S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Journal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded（轰炸）with newspaper articles, television shows and films, as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cloning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like,But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool, answer the pro-cloners（赞成克隆的人）.Richard Seed's announcement received_______.A:the nucleus of a cellB:cloned human beingsC:a human being in two yearsD:a law to ban human cloningE:a report on human cloningF:heavy media coverage

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考题共用题干 Cloning（克隆）:Future Perlect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves（牛犊）using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clone a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative,In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U. S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Journal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded（轰炸）with newspaper articles, television shows and films, as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cloning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like,But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool, answer the pro-cloners（赞成克隆的人）.Paragraph 2________A:Strong reactionsB:Anxiety about the future if cloningC:The right to chooseD:What id cloning?E:Arguments in favor of cloningF:A common sight

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考题共用题干 Cloning（克隆）:Future Pertect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves（牛犊）using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clonen a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative.In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U.S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Joumal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded（轰炸）with newspaper articles , television shows and films , as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cioning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like.But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool , answer the pro-cloners（赞成克隆的人）. Paragraph 3_________A:Strong reactionsB:Anxiety about the future of cloningC:The right to chooseD:What is cloning?E:Arguments in favor of cloningF:A common sight

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考题共用题干 Cloning（克隆）:Future Pertect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves（牛犊）using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clonen a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative.In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U.S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Joumal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded（轰炸）with newspaper articles , television shows and films , as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cioning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like.But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool , answer the pro-cloners（赞成克隆的人）. Within ten years scientists will probably have______.A:the nucleus of a cellB:cloned human beingsC:a human being in two yearsD:a law to ban human cloningE:a report on human cloningF:heavy media coverage

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考题共用题干 Cloning（克隆）:Future Pertect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves（牛犊）using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clonen a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative.In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U.S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Joumal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded（轰炸）with newspaper articles , television shows and films , as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cioning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like.But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool , answer the pro-cloners（赞成克隆的人）. Richard Seed's announcement received_________.A:the nucleus of a cellB:cloned human beingsC:a human being in two yearsD:a law to ban human cloningE:a report on human cloningF:heavy media coverage

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考题 As they had run out of sugar, they used honey as a（n） ______ for it.A.exchange B.assistance C.substitute D.preference

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考题共用题干 The Tough Grass That Sweetens Our LivesSugar cane was once a wild grass that grew in New Guinea and was used by local people for roofing their houses and fencing their gardens. Gradually a different variety evolved which contained sucrose（蔗糖） and was chewed on for its sweet taste.Over time,sugar cane became a highly valuable commercial plant,grown throughout the world.___________(46)Sugar became a vital ingredient in all kinds of things , from confectionery（糖果点心）to medicine, and,as the demand for sugar grew,the industry became larger and more profitable.________(47)Many crops withered（枯萎）and died,despite growers'attempts to save them,and there were fears that the health of the plant would continue to deteriorate.In the 1960s,scientists working in Barbados looked for ways to make the commercial species stronger and more able to resist disease.They experimented with breeding programmes,mixing genes from the wild species of sugar cane,which tends to be tougher,with genes from the more delicate,commercial type. ________(48)This sugar cane is not yet ready to be sold commercially,but when this happens,it is expected to be incredibly profitable for the industry.__________(49)Brazil,which produces one quarter of the world's sugar,has coordinated an interna-tional project under Professor Paulo Arrudo of the Universidade Estaudual de Campinas in Sao Paulo.Teamsof experts have worked with him to discover more about which parts of the genetic structure of the plant are important for the production of sugar and its overall health.Despite all the research,however,we still do not fully understand how the genes act in sugar cane._________(50)This gene is particularly exciting because it makes the plant resistant to rust,a disease which probably originated in India,but is now capable of infecting sugar cane across the world.Scientists believe they will eventually be able to grow a plant which cannot be destroyed by rust._________（46）A:Eventually,a commercial plant was developed which was 5 percent sweeter than before,but also much stronger and less likely to die from disease.B:Unfortunately,however,the plant started to become weaker and more prone to disease.C: One major gene has been identified by Dr Angelique D, Hont and her team in Montpelier, France.D:The majority of the world's sugar now comes from this particular commercial species.E:Sugar cane is now much more vigorous and the supply of sugar is therefore more guaranteed.F: Since the 1960s,scientists have been analysing the mysteries of the sugar cane'S genetic code.

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考题共用题干 Unlocking the Human Genome（基因组）1 A project to unlock secrets一what scientist could resist that challenge?This is what many scientists are doing as they work on the Human Genome Project.The aim of the project is to decode（破译）all of the some 100,000 genes in the human body. Scientists are using DNA fingerprinting techniques to do the decoding.2 DNA is the substance found in the chromosomes（染色体）of a cell. A chromosome is a chain of genes.Each gene carries a piece of genetic information.At any one moment in a cell, thousands of genes are turned on and off to produce proteins（蛋白质）.The challenge for scientists is to find out what role each gene plays in protein production.At some point this decoding will be complete.Then scientists will have a map of an ideal genome,or a picture of the total genetic nature of a human being.The ideal genome is called a consensus（交感）genome. Everything works well in a consensus genome.3 But no one in the world has a consensus genome.Everyone's genome is different from the ideal. These differences are referred to as genetic mutations（突变）.Genetic mutations in a person's genome mean that the person has a greater than average chance of suffering from health problems.Some problems are not life-threatening.These would include things like colorblindness,or mild headaches.Other problems are serious,such as heart disease,or cancer.4 It will take years to identify the role of each of the 100,000 genes.The short-term goal of the project is to find the physical and mental health problems a person is likely to encounter during his or her lifetime.The long-term goal is to have each person live a longer,healthier life.The Human Genome Project is trying to map all_________that make us human.A:that person's healthB:a scientific answerC:scientific researchersD:the genesE:the functionF:the size

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考题共用题干 Unlocking the Human Genome（基因组）1 A project to unlock secrets一what scientist could resist that challenge?This is what many scientists are doing as they work on the Human Genome Project.The aim of the project is to decode（破译）all of the some 100,000 genes in the human body. Scientists are using DNA fingerprinting techniques to do the decoding.2 DNA is the substance found in the chromosomes（染色体）of a cell. A chromosome is a chain of genes.Each gene carries a piece of genetic information.At any one moment in a cell, thousands of genes are turned on and off to produce proteins（蛋白质）.The challenge for scientists is to find out what role each gene plays in protein production.At some point this decoding will be complete.Then scientists will have a map of an ideal genome,or a picture of the total genetic nature of a human being.The ideal genome is called a consensus（交感）genome. Everything works well in a consensus genome.3 But no one in the world has a consensus genome.Everyone's genome is different from the ideal. These differences are referred to as genetic mutations（突变）.Genetic mutations in a person's genome mean that the person has a greater than average chance of suffering from health problems.Some problems are not life-threatening.These would include things like colorblindness,or mild headaches.Other problems are serious,such as heart disease,or cancer.4 It will take years to identify the role of each of the 100,000 genes.The short-term goal of the project is to find the physical and mental health problems a person is likely to encounter during his or her lifetime.The long-term goal is to have each person live a longer,healthier life.Decoding the human genome is a challenge to_________.A:that person's healthB:a scientific answerC:scientific researchersD:the genesE:the functionF:the size

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考题共用题干 Unlocking the Human Genome（基因组）1 A project to unlock secrets一what scientist could resist that challenge?This is what many scientists are doing as they work on the Human Genome Project.The aim of the project is to decode（破译）all of the some 100,000 genes in the human body. Scientists are using DNA fingerprinting techniques to do the decoding.2 DNA is the substance found in the chromosomes（染色体）of a cell. A chromosome is a chain of genes.Each gene carries a piece of genetic information.At any one moment in a cell, thousands of genes are turned on and off to produce proteins（蛋白质）.The challenge for scientists is to find out what role each gene plays in protein production.At some point this decoding will be complete.Then scientists will have a map of an ideal genome,or a picture of the total genetic nature of a human being.The ideal genome is called a consensus（交感）genome. Everything works well in a consensus genome.3 But no one in the world has a consensus genome.Everyone's genome is different from the ideal. These differences are referred to as genetic mutations（突变）.Genetic mutations in a person's genome mean that the person has a greater than average chance of suffering from health problems.Some problems are not life-threatening.These would include things like colorblindness,or mild headaches.Other problems are serious,such as heart disease,or cancer.4 It will take years to identify the role of each of the 100,000 genes.The short-term goal of the project is to find the physical and mental health problems a person is likely to encounter during his or her lifetime.The long-term goal is to have each person live a longer,healthier life.Scientists are trying hard to discover_________of each of the genes in our body.A:that person's healthB:a scientific answerC:scientific researchersD:the genesE:the functionF:the size

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考题共用题干 The Tough Grass that Sweetens Our LivesSugar cane was once a wild grass that grew in New Guinea and was used by local people for roofing their houses and fencing their gardens. Gradually a different variety evolved which contained sucrose（蔗糖）and was chewed on for its sweet taste.Over time,sugar cane became a highly valuable commercial plant,grown throughout the world.___________(46)Sugar became a vital ingredient in all kinds of things, from confectionery（糖果点心）to medicine, and,as the demand for sugar grew,the industry became larger and more profitable._________(47)Many crops withered（枯萎）and died,despite growers'attempts to save them,and there were fears that the healthof the plant would continue to deteriorate.In the 1960s,scientists working in Barbados looked for ways to make the commercial species stronger and more able to resist disease.They experimented with breeding programmes,mixing genes from the wild species of sugar cane,which tends to be tougher,with genes from the more delicate,commercial type. _________(48)This sugar cane is not yet ready to be sold commercially,but when this happens,it is expected to be incredibly profitable for the industry.___________(49)Brazil,which produces one quarter of the world's sugar,has coordinated an interna- tional project under Professor Paulo Arrudo of the Universidade Estaudual de Campinas in Sao Paulo.Teams of experts have worked with him to discover more about which parts of the genetic structure of the plant are important for the production of sugar and its overall health.Despite all the research,however,we still do not fully understand how the genes function in sugar cane.__________(50)This gene is particularly exciting because it makes the plant resistant to rust,a dis- ease which probably originated in India,but is now capable of infecting sugar cane across the world.Scien- tists believe they will eventually be able to grow a plant which cannot be destroyed by rust.__________(46)A:The majority of the world's sugar now comes from this particular commercial species.B:Unfortunately,however,the plant started to become weaker and more prone to disease.C:Eventually,a commercial plant was developed which was 5 percent sweeter than before,but also much stronger and less likely to die from disease.D:Since the 1960s,scientists have been analysing the mysteries of the sugar cane's genetic code.E:One major gene has been identified by Dr Angelique D'Hont and her team in Montpelier,France.F: Sugar cane is now much more vigorous and the supply of sugar is therefore more guaranteed.

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考题 The writer holds that the potential to make healthy body tissues will( ) A.aggravate moral issues of human cloning B.bring great benefits to human beings C.help scientists decode body instructions D.involve employing surgical instruments

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考题单选题According to scientists diabetes causes all the following EXCEPT_____.A lack of insulinB accumulation of sugar energyC brain damagesD disorder in the immune system

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考题单选题One problem of using pig organs on humans is ______.A the size of the pig organs.B the quick rejection of the transplant by human bodies.C the speed of their maturity.D the technical complexity of the operational process.

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考题问答题Practice 1　　After nearly a year of emotional arguments in Congress but no new federal laws the national debate over the future of human cloning has shifted to the states. Six states have already banned cloning in one form or another，and this year alone 38 anticloning measures were introduced in 22 states.　　The resulting patchwork of laws，people on all sides of the issue say，complicates a nationwide picture already clouded by scientific and ethnical questions over whether and how to restrict cloning or ban it altogether.　　Since l997，when scientists announced the birth of Dolly the sheep，the first cloned mammal，the specter of cloned babies, infants that ate，in essence，genetic carbon copies of adults has loomed large in the public psyche and in the minds of lawmakers.　　Today, there is widespread agreement that cloning fur reproduction is unsafe and should be banned. Now，the debate has shifted away from the ethics of baby-making and toward the morality of cloning embryos for their cells and tissues，which might be used to treat diseases. The controversy pits religious c6nservatives and abortion opponents, who regard embryos as nascent human life，against patients' groups，scientists and the biotechnology industry.

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考题单选题Scientists find that it is possible to cure diabetes by means of _____.A operation on pancreasB stopping the accumulation of blood cellsC accumulation sugar energyD preventing the immune system from making mistakes

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考题单选题Sugar manufactures have ______.A tried hard to make experiments on their own with sugar on humans and animalsB invested millions of dollars in buying best names of scientists to sell sugar.C hoped to encounter some scientific findings about sugar.D tried hard to establish public relations in order to open the market for sugar.

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更多 “单选题PPL scientists will try to solve their problem by ______.A removing the sugar molecule on the surface of pig cells.B distinguishing human tissues form those of pigs.C using the sugar-free nucleus in cloning a pig.D taking out the sugar genes from the cell of a pig.” 相关考题

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