Genes fromvirtuallyanyorganism, from viruses to humans, can now be inserted into plants, creating what are known as transgenic plants. Now used inagriculture, there areapproximately109 million acres of transgenic crops grown worldwide, 68 percent of which are in the United States. The mostcommontransgenic crops are soybeans, corn, cotton, and canola. Most often, these plants eithercontainagenemaking themresistantto theherbicideglyphosateor theycontainan insect-resistantgenethat produces aproteincalled Bt toxin.

On thepositiveside, proponents of transgenic cropsarguethat these crops are environmentally friendly because they allow farmers to use fewer and lessnoxiouschemicals for crop production. For example, a 21 percentreductionin the use of insecticide has been reported on Bt cotton (transgenic cotton that produces Bt toxin). Inaddition, whenglyphosateis used to control weeds, other morepersistentherbicides do not need to be applied.

On thenegativeside, opponents of transgenic crops suggest that there are many questions that need to be answered before transgenic crops are grown on a largescale. One question deals with the effects that Bt plants have on nontarget organisms such asbeneficialinsects, worms, and birds thatconsumethegeneticallyengineered crop. For example,monarchcaterpillars feeding on milkweed plants near Bt cornfields will eat some cornpollenthat has fallen on the milkweed leaves. Laboratorystudiesindicatethat caterpillars can die from eating Btpollen. However,fieldtestsindicatethat Bt corn is not likely to harm monarchs. Furthermore, theapplicationof pesticides (thealternativeto growing Bt plants) has been demonstrated to causewidespreadharm to nontarget insects.

Another unanswered question is whether herbicide-resistant genes will move into the populations of weeds. Crop plants are sometimes grown in areas where weedy relatives also live. If the crop plants hybridize andreproducewith weedy relatives, then this herbicide-resistantgenewill be perpetuated in theoffspring. In this way, theresistantgenecan make its way into theweedpopulation. If this happens, a farmer can no longer useglyphosate, for example, to kill those weeds. Thisscenariois not likely tooccurin many instances because there are no weedy relatives growing near the crop plant. However, in some cases, it may become a serious problem. For example, canolareadilyhybridizes with mustardweedspeciesand couldtransferits herbicide-resistant genes to those weeds.

We know thatevolutionwilloccurwhen transgenic plants grown on a largescaleover a period of time. Ofspecialconcernis thedevelopmentofinsectpopulationsresistantto the Bt toxin. Thispesticidehas been applied to plants for decades without thedevelopmentof insect-resistant populations. However, transgenic Bt plants express the toxin in all tissuesthroughoutgrowingseason. Therefore, all insects carrying genes that make themsusceptibleto the toxin will die. That leaves only thegeneticallyresistantinsects alive toperpetuatethepopulation. When theseresistantinsectsmate, they will produce a highproportionofoffspringcapableof surviving in the presence of the Bt toxin. Farmers are attempting to slow thedevelopmentofinsectresistancein Bt crops by, for example, planting nontransgenicborderrows to provide a refuge forsusceptibleinsects. These insects may allow Btsusceptibilitytoremainin thepopulation.

Perhaps the most seriousconcernabout the transgenic crop plants currently in use is that theyencouragefarmers to move farther away from sustainable agricultural farming practices, meaning ones that allow natural resources to continuallyregenerateover the long run. Transgenics, atleastsuperficially,simplifyfarming by reducing the choices made by the manager. Planting a glyphosate-resistant crop commits a farmer to using thatherbicidefor thereason, probably to the exclusion of all other herbicides and other weed-control practices. Farmers who use Bt transgenics may not feel that they need to followthroughwith integrated pest-management practices that usebeneficialinsects and timely applications of pesticides to controlinsectpests. A more sustainableapproachwould be to plant nontransgenic corn,monitorthe fieldsthroughoutthe growingseason, and thenapplyapesticideonly if and when needed.

Questions:
question_stem: According to paragraph 1, which of the following is true of transgenic plants that produce the protein Bt?
choices: tag: A
text: They are resistant to certain herbicides.

tag: B
text: They grow best in the United States.

tag: C
text: They were treated with the chemicals glyphosate.

tag: D
text: They are resistant to destruction by insects.
answer_key: D
explanation: 【题目翻译】根据第1段，以下哪一项对于产生 Bt 蛋白的转基因植物是正确的？
A：它们对某些除草剂有抵抗力。

B：它们在美国生长得最好。

C：用草甘膦处理。

D：它们能抵抗昆虫的破坏。

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】本题根据题干给出的两个关键词 transgenic plants 和 protein Bt 定位到原文中的第一段，第一段里出题点在这半句话：they contain an insect-resistant gene that produces a protein called Bt toxin。意思是“含有 Bt 蛋白质基因的植物可以抵抗害虫”。

【逻辑分析】文章意思很明显：含有 Bt 蛋白质基因的植物可以抵抗害虫。

【选项分析】
A.选项 A 说它们可以抵抗除草剂，不符，错误
B.选项 B 说它们在美国生长地最好，不符，错误
C.选项 C 说它们被施加了一种农药草甘膦，不符合原文意思。
D.选项 D 符合。选择 D。

question_stem: According to paragraph 2, supporters claim that producing transgenic plants enables farmers to
choices: tag: A
text: increase crop production by up to 21 percent

tag: B
text: use fewer and less toxic chemicals

tag: C
text: control weeds without the use of glyphosate

tag: D
text: take advantage of more effective herbicides
answer_key: B
explanation: 【题目翻译】根据第2段，支持者声称生产转基因植物能使农民
A：作物产量增加21%

B：使用越来越少的有毒化学品

C：不使用草甘膦控制杂草

D：利用更有效的除草剂

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】本题根据题干给的关键词 enable farmers 定位到这一句：On the positive side, proponents of transgenic crops argue that these crops are environmentally friendly because they allow farmers to use fewer and less noxious chemicals for crop production.意思是“转基因作物的支持者说这些植物是环境友好的，因为它们可以让使用的农药量变少”。

【逻辑分析】：结合题目问法和出题句，进行逻辑分析。

【选项分析】
A.选项 A 说可以增加产量，不符，错误。
B.选项 B 是正确的同义转述。正确。
C.选项 C 说可以不用草甘膦控制野草，不符，错误。
D.选项 D 说可以利用更有效果的除草剂，不符，错误。

question_stem: The word "persistent" in the passage in closest in meaning to
choices: tag: A
text: harmful

tag: B
text: long lasting

tag: C
text: expensive

tag: D
text: hard to control
answer_key: B
explanation: 【题目翻译】在文章中“persistent”一词最接近于
选项 A 是有害的，
选项 B 是长期的持久的，
选项 C 是贵的，
选项 D 是难以控制的。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“persistent”,定位到原句“In addition, when glyphosate is used to control weeds, other, more persistent herbicides do not need to be applied.。

【词汇解析】：词汇“persistent”的意思是“长时间的”,带入到原句中，原句的意思是“另外，草甘膦被用于控制杂草时，其他的更加效果持久的除草剂就不需要再用了”。

【选项分析】
选项 A 是有害的，不符，错误
选项 B 是长期的持久的，同义替换，正确
选项 C 是贵的，不符，错误
选项 D 是难以控制的，不符，错误

question_stem: Which of the following can be inferred about monarch caterpillars from paragraph 3?
choices: tag: A
text: They often cause damage to corn crops.

tag: B
text: They are the only species that is immune to Bt toxin.

tag: C
text: They are considered beneficial insects.

tag: D
text: Their reactions to Bt pollen have not yet been studied.
answer_key: C
explanation: 【题目翻译】以下哪一项可以从第3段推断出帝王毛虫？
A：它们经常对玉米作物造成损害。

B：它们是唯一对 bt 毒素免疫的物种。

C：它们被认为是有益的昆虫。

D：它们对 Bt 花粉的反应还没有研究。

【判定题型】：根据题干中出现的关键词“imply”/“infer”/“suggest”等其他表示推断的词，判定本题为推理题。

【关键词定位】本题根据题干所给关键词 monarch caterpillar 进行定位，找到原文中这一句：For example, monarch caterpillars feeding on milkweed plants near Bt cornfields will eat some com pollen that has fallen on the milkweed leaves. 

【逻辑分析】for example 告诉我们 monarch caterpillar 是作为例子去证实前一句所说的 Bt plants have on nontarget organisms such as beneficial insects, worms, and birds that consume the genetically engineered crop 的。

【选项分析】
A.文章未提及，故错误
B.文章未提及，故错误
C.monarch caterpillar 在这里是作为有益处昆虫出现的，选项 C 符合。
D.文章未提及，故错误

question_stem: What conclusion does the author make in paragraph 3 about the effect of Bt plants on notarget organisms?
choices: tag: A
text: Bt toxins do not affect nontarget organisms because the toxins only harm pests that eat the leaves, stems, or fruit of the plants.

tag: B
text: Bt plants have been shown in field studies to cause great harm to nontarget organisms.

tag: C
text: Bt plants do not cause as much harm to nontarget species as the use of conventional pesticides.

tag: D
text: Even if Bt toxins do not affect the insects that feed on the plants, they have harmful effects on birds that eat these insects.
answer_key: C
explanation: 【题目翻译】作者在第3段中对 bt 植物对非目标生物体的影响作了什么结论？
A：Bt 毒素不会影响非目标生物，因为这些毒素只会伤害吃植物叶、茎或果实的害虫。

B：Bt 植物已在野外研究中被证明对非目标生物有很大的危害。

C：BT 植物对非目标物种的危害没有传统杀虫剂那么大。

D：即使 bt 毒素不会影响以植物为食的昆虫，它们也会对吃这些昆虫的鸟类产生有害影响。

【判定题型】：题目问的是文章中的具体细节信息，故根据题目问法可以判断本题为事实信息题。

【关键词定位】本题的出题点在第五段最后两句：However, field tests indicate that Bt corn is not likely to harm monarchs. Furthermore, the application of pesticides (the alternative to growing Bt plants) has been demonstrated to cause widespread harm to nontarget insects. 意思是“然而，田间试验表明，Bt 玉米不太可能危害帝王。此外，杀虫剂（替代种植 Bt 植物）的应用已被证明对非目标昆虫造成了广泛的危害”。

【逻辑分析】这两句对比说明 Bt 作物不会伤害毛毛虫，但是杀虫剂的使用是会伤害它们这种非靶向物种的。

【选项分析】
A.选项 A 说 Bt 物质不会伤害非靶向物种，错误，只是伤害比杀虫剂小而已；
B.选项 B 说 Bt 物质杀伤力非常大，错误，其实并不大；
C.选项 C 说 Bt 植物对非靶向物种的伤害比杀虫剂小，正确。
D.选项 D 说即使 Bt 物质不伤害以这种作物为食的昆虫，但是会伤害鸟类，错误。

question_stem: The word "perpetuated" in the passage is closest in meaning to
choices: tag: A
text: continued

tag: B
text: reproduced

tag: C
text: observed

tag: D
text: spread
answer_key: A
explanation: 【题目翻译】文章中“perpetuated”一词与下列哪个词意思最相近？
选项 A 是持续的，
选项 B 是再生产的，
选项 C 是观察的，
选项 D 是传播的。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“perpetuated”,定位到原句“If the crop plants hybridize and reproduce with weedy relatives, then this herbicide-resistant gene will be perpetuated in the offspring. ”。

【词汇解析】：词汇“perpetuated”的意思是“不朽，长存”,带入到原句中，原句的意思是“如果农作物与杂草杂交，然后这种抗除草剂的基因就会一直保存在后代身上”。

【选项分析】
选项 A 是持续的，同义替换，正确
选项 B 是再生产的，不符， 错误
选项 C 是观察的，不符， 错误
选项 D 是传播的，不符， 错误

question_stem: The word "scenario" in the passage is closest in meaning to
choices: tag: A
text: effect

tag: B
text: problem

tag: C
text: resistance

tag: D
text: situation
answer_key: D
explanation: 【题目翻译】文章中“scenario”一词与下列哪个词意思最相近？
选项 A 的意思是影响，
选项 B 的意思是问题，
选项 C 的意思是阻力，
选项 D 的意思是场景。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“scenario”,定位到原句“This scenario is not likely to occur in many instances because there are no weedy relatives growing near the crop plant.”。

【词汇解析】：词汇“scenario”的意思是“情景，场景，情况”,带入到原句中，原句的意思是“这种情况不容易广泛发生，因为在这种作物周围一般是没有杂草存在的”。

【选项分析】
选项 A 的意思是影响，不符，错误
选项 B 的意思是问题，不符，错误
选项 C 的意思是阻力，不符，错误
选项 D 的意思是场景，符合，正确

question_stem: Why does the author mention "mustard weed species" in the discussion of plants that hybridize?
choices: tag: A
text: To give an example of a weed that may become resistant to glyphosate due to hybridizing with a transgenic plant.

tag: B
text: To argue that creating transgenic plants in the laboratory is not always necessary, as some can be created through hybridizing in the fields.

tag: C
text: To provide evidence that competition from related species of plants can be a serious problem for transgenic plants.

tag: D
text: To support the claim that it is difficult to determine whether or not a crop plant has been planted a safe distance from weedy relatives.
answer_key: A
explanation: 【题目翻译】为什么作者在讨论杂交植物时提到“芥子杂草物种”？
A：举一个杂草的例子，这种杂草可能由于与转基因植物杂交而对草甘膦产生抗药性。

B：认为在实验室培育转基因植物并不总是必要的，因为有些植物可以通过田间杂交来培育。

C：为转基因植物的竞争提供证据。

D：为了支持这样一种说法，即很难确定是否种植了一种与杂草亲戚保持安全距离的作物。

【判定题型】：根据题干问法“why …… mention”，题目询问“xxxxxx”(文章引用内容)的修辞目的，可以判断本题为修辞目的题。

【关键词定位】本题题干给的关键词是 mustard weed species 和 hybridize，带着关键词回溯原文，找到这里：For example, canola readily hybridizes with mustard weed species and could transfer its herbicide-resistant genes to those weeds. 

【引用内容分析】结合前文，本句的大意是：例如 canola 这种作物就可以与 mustard 这种杂草杂交，把它的抗除草剂基因传给这种杂草。所以作者在这里的意思是举例杂交可以使得杂草具有抗除草剂的基因。

【选项分析】
A.符合文意，正确。
B.选项 B 说为了论证没必要创造转基因作物，不符，错误
C.选项 C 说为了证明相关物种和转基因作物的竞争很重要，不符，错误
D.选项 D 说为了支持很难把作物和杂草隔开一段安全距离种植，不合原文意思。错误

question_stem: Paragraph 5 makes all of the following claims about Bt resistance in insect populations EXCEPT
choices: tag: A
text: Regular use of Bt pesticides has not created resistant insect populations, so the use of Bt plants is probably safe as well.

tag: B
text: The evolution of Bt-resistant insect populations will happen eventually if use of transgenic plants becomes widespread.

tag: C
text: Because Bt plants are toxic at all times and in all tissues, they allow only Bt-resistant insects to survive and reproduce.

tag: D
text: Planting nontransgenic plants alongside Bt plants may help Bt-susceptible insects to remain part of the population.
answer_key: A
explanation: 【题目翻译】第5段对昆虫种群的 Bt 抗性提出了以下所有要求，除了
A：经常使用 Bt 杀虫剂并没有产生抗药性的昆虫种群，因此使用 Bt 植物可能也是安全的。

B：如果转基因植物的广泛使用，最终会发生抗 Bt 昆虫种群的进化。

C：因为 bt 植物在任何时候和所有组织中都是有毒的，它们只允许抗 bt 的昆虫生存和繁殖。

D：在 Bt 植物旁边种植非转基因植物可能有助于 Bt 易感昆虫保持种群的一部分。

【判定题型】：根据题干中出现的大写“EXCEPT”/"NOT" 等其他明显表示否定的词，可以判定本题为否定事实信息题，需要找出与原文信息不符的那个答案。

【关键词定位】：根据题干关键词“Bt resistance”,可以将出题范围锁定在 Passage5。

【选项分析】
选项 A 涉及到 Bt 杀虫剂不会导致昆虫产生抗性，所以具有 Bt 基因的作物的使用是安全的，不对，Bt 基因作物的使用是有风险的，整段都在讲这种作物使昆虫产生抗药性的事情；选择 A。
选项 B 涉及到 We know that evolution will occur when transgenic plants grown on a large scale over a period of time，是这句话的同义转述，正确；
选项 C 是涉及到 However, transgenic Bt plants express the toxin in all tissues throughout growing season. Therefore, all insects carrying genes that make them susceptible to the toxin will die.Bt 基因的作物会杀死除了带有抗性基因的所有昆虫，正确；
选项 D 依据 for example, planting nontransgenic border rows to provide a refuge for susceptible insects，种植不带转基因的作物使解决办法之一，正确。

question_stem: Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
choices: tag: A
text: The transgenic crop plants currently in use are probably far behind the transgenic plants of the future in terms of their sustainability.

tag: B
text: Farmers who use transgenic crop plants are heading toward practices that allow natural resources to continually regenerate over the long run.

tag: C
text: Transgenic crop plants may be used in place of other, more sustainable agricultural practices, and this is perhaps their biggest disadvantage.

tag: D
text: Perhaps the most serious concern about the transgenic crop plants currently in use is the possibility that they may not be sustainable over the long run.
answer_key: C
explanation: 【题目翻译】下面哪句话最能表达文章中突出显示的句子中的基本信息？错误的选择会以重要的方式改变意义，或者遗漏重要的信息。
A：就可持续性而言，目前使用的转基因作物可能远远落后于未来的转基因植物。

B：使用转基因作物的农民正朝着允许自然资源长期持续再生的实践迈进。

C：转基因作物可以用来替代其他更可持续的农业做法，这可能是它们最大的缺点。

D：也许对目前使用的转基因作物最严重的担忧是它们可能长期不可持续。

【判定题型】：根据题目问法，题目要求选择和高亮句意思逻辑都最为接近的句子，故判断本题为句子简化题。

【句子分析】本题根据所考察的单词定位到这一句：Perhaps the most serious concern about the transgenic crop plants currently in use is that they encourage farmers to move farther away from sustainable agricultural farming practices, meaning ones that allow natural resources to continually regenerate over the long run. 这句话的大体意思是：也许转基因作物带来的最严重问题是，它让农民开始放弃可持续性的耕作方式，放弃了那种可以让自然资源在长期自己再生的那种耕作方式。

【选项分析】
A.A 选项说现在用的转基因作物比将来的可持续性差，是原句未提及的新比较； 
B. B 选项说农民将要进行可持续的耕作活动，意思与原句相悖；
C.选项 C 是本句的同义转述。C 选项说转基因作物可以被用来代替更有持续性的农业实践，这是转基因作物最大的问题。正确改写原句，正确。 
D.D 选项说，对于目前正在使用的转基因作物，最严重的担忧可能是，长期来看，转基因作物可能不可持续。选项是对转基因作物本身是否可持续的判断，而原句是说的是耕作方式，对象不同，不能混淆。

question_stem: According to paragraph 6, a sustainable approach to weed and pest control includes all of the following EXCEPT
choices: tag: A
text: watching the fields closely to determine when weeds or pests are actually a problem

tag: B
text: applying pesticides unless or until pesticides are needed

tag: C
text: using only one type of herbicide throughout the growing season

tag: D
text: planting nontransgenic crops
answer_key: C
explanation: 【题目翻译】根据第6段，杂草和害虫防治的可持续方法包括以下所有方法，除了
A：仔细观察田地，确定杂草或害虫实际上是什么问题。

B：除非或直到需要杀虫剂时才使用杀虫剂。

C：整个生长季节只使用一种除草剂

D：种植非转基因作物

【判定题型】：根据题干中出现的大写“EXCEPT”/"NOT" 等其他明显表示否定的词，可以判定本题为否定事实信息题，需要找出与原文信息不符的那个答案。

【关键词定位】：根据题干关键词 sustainable approach，可以将出题范围锁定在 Passage 6。

【选项分析】：
A.选项 A 的依据是 monitor the fields throughout the growing season，即全程监控作物生长情况；
B.选项 B 的依据是 then apply a pesticide only if and when needed，即只在需要的时候使用杀虫剂；
C.选项 C 说的一个耕作季节只用一种杀虫剂，根据前文我们知道这样很容易让昆虫剩下全是抗性的昆虫，错误。选择 C。
D.选项 D 的依据是 A more sustainable approach would be to plant nontransgenic corn，耕作无转基因的作物。

question_stem: The word "superficially" in the passage is closest in meaning to
choices: tag: A
text: in the opinion of experts

tag: B
text: at the present moment

tag: C
text: when done properly

tag: D
text: without deeper analysis
answer_key: D
explanation: 【题目翻译】文中“superficially”与下列哪一个意思最相近？
选项 A 是根据专家意见，
选项 B 是在当前，
选项 C 是当恰当地做以后，
选项 D 是没有更深的分析。

【判定题型】：题目要求选出与高亮单词意思最接近的选项，故判断本题为词汇题。

【关键词定位】：根据关键词“superficially”,定位到原句“Transgenics, at least superficially, simplify farming by reducing the choices made by the manager. ”。

【词汇解析】：词汇“superficially”的意思是“表面上”,带入到原句中，原句的意思是“转基因，最起码在表面上通过减少管理者的可选项而简化了耕作过程（本句意思较抽象，具体而言是：选择了具有哪种农药抗性的作物，使用的农药种类就固定了，只能用作物具有抗性的那一种，因此农民不需要再在多种农药中选择了）”。

【选项分析】
选项 A 是根据专家意见，不符，错误
选项 B 是在当前，不符，错误
选项 C 是当恰当地做以后，不符，错误
选项 D 是没有更深的分析。同义替换，正确