单选题Why switch grass and Miscanthus were taken as energy plant?A Because they contain more cellulose.B Because genomes have been sequenced for clues to make other plants better energy crops.C Because some scientists are breeding a wide variety o[Candidate crops.D Because the spotlight is on this underdeveloped field.

考题 —Why does the stream smell terrible? —Because large quantities of water_____. A、have pollutedB、is being pollutedC、has been pollutedD、have been polluted

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考题 Why does it take long for people to change their food?A． Because labs are not easily accessible to researchers.B． Because some people are reluctant to accept the new diet.C． Because food consumption is a culture of conservation.D． Because some scientists are against the growing lab meat.

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考题 Why did American city residents want to live in the suburbs after World War Ⅱ?A. Because older American cities were dying.B. Because they were richer and needed more space.C. Because cities contained the wont pare of society.D. Because they could hardly afford a live in the city.

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考题 We can use energy from the sun because ______.

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考题 25． Why do we call the sun"a life-giving star"?A． Because it gives us warmth．B． Because there are some living things on it．C． Because plants and animals can't live without it．D． Because people have to live in the dark without it．

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考题 Why does author say that they were lucky in the third paragraph?A. Because her situation was not serious.B. Because many other places were flooded.C. Because she had been to Northern India.D. Because some others suffered even more.

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考题 Why do the depository institutions have the fractional reserve banking?A．Because they can keep a large amount of deposits from their depositors in the form. of reserves.B．Because most of their depositors would withdraw their deposits.C．Because only a small fraction of their depositors would deposit money during a day or week.D．Because they can meet the need of withdrawing of their depositors and make investments in other financial assets.

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考题 Most animals have little connection with animals of different kind, unless they hunt them for food. Sometimes, however, two kinds of animals come together in a partnership ( 伙伴关系 ) which does good to both of them. You may have noticed some birds sitting on the backs of sheep. This is not because they want a ride, but because they find easy food in the parasites (寄生虫 ) on sheep. The sheep allow the birds to do so because they remove the cause of discomfort. So although they can manage without each other, they do better together.Sometimes an animal has a plant partner. The relationship develops until the two partners cannot manage without each other. This is so in the corals ( 珊瑚 ) of the sea. In their skins they have tiny plants act as "dustman", taking some of the waste products form. the corals and giving in return oxygen which the animal needs to breathe. If the plants are killed, or are ever prevented from lighting so that they cannot live normally, the corals will die.1、Some birds like to sit on a sheep because ( ).A、they can eat its parasitesB、 they depend on the sheep for existenceC、 they enjoy traveling with the sheepD、 they find the position most comfortable2、The underlined word "they" in the last sentence of the first paragraph refers to ( ).A、birds and parasitesB、birds and sheepC、parasites and sheepD、sheep, birds and parasites3、What does the second paragraph mainly discuss? ( )A、Some animals and plants depend on each other for existence.B、 Some animals and plants develop their relationship easily.C、 Some plants depend on each other for fooD、 Some animals live better together.4、What does this article talk about? ( )A、Two kinds of animals for a partnership.B、Most animals only have connection with animals.C、The connection between the living things.D、Corals have some connection with plants.

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考题 Refer to the exhibit. Based on the information given. Which switch will be elected root bridge and why?() A.Switch A ,because it has the lowest MAC addressB.Switch C,because it has the lowest priorityC.Switch B,because it has the highest MAC addressD.Switch C,because it is the most centrally located switchE.Switch A,because it is the most centrally located switchF.Switch D,because it has the highest priority

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考题 AWhy do plants grow in some places and not in others? Why does some land have so much growing on it，while other land has almost no plants growing on it at all?To grow plants need several things． One is warmth． In very cold places almost nothing grows． Plants also need water． In very dry parts of the earth only a few unusual plants can grow． That's why dry deserts everywhere are almost not covered by trees or grass．Plants must also have a place in which to f，ut down their roots and grow． They find it diffi-culr to grow on hard land． The town is built on hard land． The plants here have only the soil found between the cracks of the stones Io grow in．Another thing plants must have before they can grow is food．Whar will happen if we try to make things grow on the sandy beach? A few plants，such as beach grass，will grow in sand，L ut most plants won-t． Even if the weather is warm enough．and we water the plants each day． Many of them will die because the sand on this beach has al-most no food for plants．( )21． According to the passage，plants need _________ things to grow well．A． twoB． threeC． fourD． five

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考题 BScientists are trying to make the deserts into good land again． They want to，bring water to the deserts． But more and more places of the earth is becoming deserts all the time， Scientists may not be able to change the deserts． Scientists think that people make deserts． People are do-ing bad things to the earth．Some places on the earth don-t get very much rain． But they still don-t become deserts．This is because some green plants are growing there． Small green plants and grass are very helpful to dry places． Plants don't let the wind blow the earth away． When 8 little bit of rain falls，the plants hold the water． Without plants，the land can become a desert much more easily．( )26． Why can the land become a desert?A． Because some places don't get very much rain．B． Because plants don-t let the hot sun make the earth even drier．C． Because people don't keep the earth well．D． Because scientists haven-t learnt enough about the deserts．

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考题 29． Why are green plants and grass helpful?A． Because they can hold the water．B． Because they can stop the wind from blowing the earth away．C． Because they can keep the earth wet．D．All the above．

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考题 Loran-C uses the multiple pulse system because ______．A.Less signal energy is necessary for receiver operationB.More signal energy is available at the receiverC.It significantly increases the peak powerD.It increases the signal capacity

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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 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

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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. 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.

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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. 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. 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 mnysterious nor magical.D:Humans have used some kinds of medicines since earliest days.

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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. It is believed by scientists that traditional medicines______.A:cancureallkindsofdiseasesB: maycuresomeoftoday,smostseriousdiseasesC: arenolongerusefulformodernmenD: aretoocheaptoheuseful

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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

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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 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 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

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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. 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.

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考题 Why were the French troops in Canada defeated by the British during theSeven Years.War?（）A、Because they were not used to the weather in Canada.B、Because they did not get support from the local people.C、Because they did not receive the supplies they needed so badly.D、Because the British had larger and better settlements in Canada.

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考题 View the Exhibit and examine the output of the query in different times when the following command runs in an RMAN sessions: RMAN BACKUP DATABASE FILESPERSET 2; The database has seven data files. Why is the %_COMPLETE refreshed to 13.59 in the third output after reaching 88.77?（）A、Because the progress is reported for each data fileB、Because the progress is reported for each backup setC、Because other RMAN sessions have issued the same BACKUP commandD、Because new data files have been added to the database while the RMAN backup is in progress

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考题单选题Her hair and coat were wet because it _____ .A would be rainingB had been rainingC would have been rainingD had rained

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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.

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