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单选题
We may infer from the fourth paragraph that ______.
A

humans have been growing food crops more than ten thousand years.

B

humans have learned how to produce biofuels for a long time.

C

humans are just on the beginning of making biofuels.

D

a cell wall includes four hemicellulose.


参考答案

参考解析
解析:
推断判断题。由题干定位至第四段。由首句Humans have been growing food crops for 10,000 years可知,A中more than与原文不符,故排除;由but the effort to produce fuel down on the farm is in its fancy可见B错;由段中 We’re at such a basic stage,可知,从作物提取燃料还处于初级阶段,C正确;由本段倒数第二句可知cell walls是由four hemicelluloses, along with cellulose and lignin构成,并且由a cell wall engineered to include more hemicellulose可知一个细胞壁不仅仅只有four hemicellulose(半纤维素), 排除D。
更多 “单选题We may infer from the fourth paragraph that ______.A humans have been growing food crops more than ten thousand years.B humans have learned how to produce biofuels for a long time.C humans are just on the beginning of making biofuels.D a cell wall includes four hemicellulose.” 相关考题
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考题 共用题干 第二篇Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine.Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospi- tals.Yet injuries are treated.And diseases are often cured.How?By ancient methods.By medicines that might seem mysterious , even magical(有魔力的).Traditional medicines are neither mysterious nor magical, however.Through the centuries, tribal(部族的)medicine men experimented with plants. They found many use- ful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment.They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store.Yet many wide- ly-used medicines are from ancient sources,especially plants.Some experts say more than 25% of modern medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory.All living things contain chemicals that help them survive.So scientists' interest in traditional medicine is not new.But it has become an ur-gent concern.This is because the earth's supply of natural medicines may be dropping rapidly. It can be seen from the passage that the earth's supply of natural medicines________.A:may never be exhaustedB:may be dropping rapidlyC:is surprisingly bigD:is as rich as ever

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考题 共用题干 Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because hu-mans have survived .Ancient treatments for injury and disease were successful enough to keep hu-mans from dying out completely.They were successful long before the time of modern medicine.Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors.Nor do they have ex- pensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient meth- ods. By medicines that might seem mysterious, even magical(有魔力的).Traditional medicines are neither mysterious nor magical,however.Through the centuries, tribal(部落的)medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80%of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment.They are used be-cause people trust them.In developed areas,few people think about the source of the medicines they buy in a store.Yet many widely-used medicines are from ancient sources,especially plants. Some experts say more than 25%of modern medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory.All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. The passage indicates that ancient treatments for injury and disease were_____.A: much more successful than modern onesB: successful enough for humans to surviveC: successful in all casesD: of little help to humans

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考题 共用题干 Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine. Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient methods. By medicines that might seem mysterious , even magical(有魔力的).Traditional medicines are neither mysterious nor magical,however.Through the centuries , tribal(部落的)medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment. They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store .Yet many widely-used medicines are from ancient sources,especially plants.Some experts say more than 25%of modem medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. It is believed by scientists that traditional medicines______.A: can cure all kinds of diseasesB: may cure some of today's most serious diseasesC: are no longer useful for modern menD: are too cheap to be useful

考题 共用题干 Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine. Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient methods. By medicines that might seem mysterious , even magical(有魔力的).Traditional medicines are neither mysterious nor magical,however.Through the centuries , tribal(部落的)medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment. They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store .Yet many widely-used medicines are from ancient sources,especially plants.Some experts say more than 25%of modem medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. It can be seen from the passage that the earth's supply of natural medicines______.A: may never be exhaustedB: may be dropping rapidlyC: is surprisingly bigD: is as rich as ever

考题 共用题干 Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine. Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient methods. By medicines that might seem mysterious , even magical(有魔力的).Traditional medicines are neither mysterious nor magical,however.Through the centuries , tribal(部落的)medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment. They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store .Yet many widely-used medicines are from ancient sources,especially plants.Some experts say more than 25%of modem medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. The passage indicates that ancient treatments for injury and disease wereA: much more successful than modem onesB: successful enough for humans to surviveC: successful in all casesD: of little help to humans

考题 共用题干 Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine. Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient methods. By medicines that might seem mysterious , even magical(有魔力的).Traditional medicines are neither mysterious nor magical,however.Through the centuries , tribal(部落的)medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment. They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store .Yet many widely-used medicines are from ancient sources,especially plants.Some experts say more than 25%of modem medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. What do the majority of the people in the world use for health care?A: Strange and wonderful equipment.B: Factory-produced chemicals.C: Modern medicines.D: Plants.

考题 共用题干 Natural MedicinesSince earliest days,humans have used some kinds of medicines.We know this because humans have survived.Ancient treatments for injury and disease were successful enough to keep humans from dying out completely.They were successful long before the time of modern medicine. Before the time of doctors with white coats and shiny(发亮的)instruments. Before the time of big hospitals with strange and wonderful equipment.Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals.Yet injuries are treated.And diseases are often cured.How?By ancient methods. By medicines that might seem mysterious , even magical(有魔力的).Traditional medicines are neither mysterious nor magical,however.Through the centuries , tribal(部落的)medicine men experimented with plants. They found many useful chemicals in the plants.And scientists believe many of these traditional medicines may provide the cure for some of today's most serious diseases.Experts say almost 80% of the people in the world use plants for health care.These natural medicines are used not just because people have no other form of treatment. They are used because people trust them. In developed areas,few people think about the source of the medicines they buy in a store .Yet many widely-used medicines are from ancient sources,especially plants.Some experts say more than 25%of modem medicines come,in one way or another,from nature.Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive .So scientists' interest in traditional medicine is not new.But it has become an urgent concern.This is because the earth's supply of natural medicines may be dropping rapidly. Which of the following statements is NOT true?A: Modern medicines are now available all over the world.B: Many big and modern hospitals are expensive.C: Traditional medicines are neither mysterious nor magical.D: Humans have used some kinds of medicines since earliest days.

考题 单选题We may infer from the second paragraph that ______.A gas price has no influence on drivers.B Toyota Yaris is not welcome in Manhattan.C Nissan Versa has already been well selling for its six-speed transmission.D Honda Fit is more economical than Chevy Suburban SUV.

考题 单选题We can infer from the passage_______.A the ice can easily just slip into the oceanB volcanoes caused the ice to meltC melting just in the Northern hemisphere would have been impossibleD researchers often use the computer models help their research work

考题 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.

考题 问答题Green Gene Technology  For the past 10,000 years humans have influenced the plants they use at first unknowingly, later by design. Today’s crops have been created by a process of selection and classical breeding. More specific improvements in breeding will be possible in future.  Science has cracked the genetic information code. Green gene technology is an effective tool in crop breeding, enabling us to develop new crops even more rapidly and specifically. We can make them more efficient, optimizing their contents and valuable substances to suit the wishes and requirements of customers and the processing industry. Their metabolism can be individually modified, making them produce starch, protein and fats with special properties. Through gene transfer plants can be made more resistant to viruses, bacteria, harmful fungi and insect pests.  Genetically modified plants can be cultivated to possess improved stress behavior, with the result that they absorb water better in dry locations and can make more efficient use of soil nutrients. We can also optimize weed control. To do so, we make crops tolerant to environmentally sound and easily degradable herbicides. This is not as simple as it sounds. But we have been successful: Innovator has been on the Canadian market since 1995. This is the first oilseed rape variety to contain the glufosinate tolerance gene, facilitating the use of AgrEvo’s broad-spectrum herbicide liberty.  We are committed to green gene technology, with which we aim to make crop breeding even more efficient and environmentally friendly. Before being brought on to the market these genetically modified plants are researched and tested for years until the questions posed regarding their safety have been answered. This is a great opportunity for us to realize our vision: the use of faster methods to breed varieties which will continue to provide us with sufficient food and raw materials in future. Our fossil reserves will soon be exhausted. Experts estimate that we only have enough oil for another 43 years and natural gas for less than 60.  This means we must rethink and act accordingly, using new crop varieties to step up the move to replenishable sources of raw materials and energy. In other words, green gene technology is the key technology for sustainable agriculture.