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和平精英左右拉枪教学视频

类型:战狼在线观看完整版52 地区: 台湾 年份:2020-07-11

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新SAT官方指南阅读第十五篇全解析This passage is adapted from Richard J.Sharpe and Lisa Heyden,“Honey Bee Colony Collapse Disorder is Possibly Caused by a Dietary Pyrethrum Deficiency.”©2009by Elsevier Ltd.Colony collapse disorder is characterized by the disappearance of adult worker bees from hives.Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor(Varroa mites).These mites feed on bee hemolymph(blood)and can kill bees directly or by increasingtheir susceptibility to secondary infection with fungi,bacteria or viruses.Little is known about the natural defenses that keep the mite infections under control.Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum,5Chrysanthemum cinerariifolium,Chrysanthemum marschalli,and related species.These plantsproduce potent insecticides with anti-mite activity.The naturally occurring insecticides are known as pyrethrums.A synonym for the naturally occurring pyrethrums is pyrethrin and syntheticanalogues of pyrethrums are known as pyrethroids.In fact,the human mite infestation known as scabies(Sarcoptes scabiei)is treated with a topical pyrethrum cream.10We suspect that the bees of commercial bee colonies which are fed mono-crops are nutritionally deficient.In particular,we postulate that the problem is a diet deficient in anti-mite toxins:pyrethrums,and possibly other nutrients which are inherent in such plants.Without,atleast,intermittent feeding on the pyrethrum producing plants,bee colonies are susceptible to mite 15infestations which can become fatal either directly or due to a secondary infection ofimmunocompromised or nutritionally deficient bees This secondary infection can be viral,bacterial or fungal and may be due to one or more pathogens.In addition,immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticidesare introduced into their hives by bee keepers in an effort to fight mite infestation.We furtherpostulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, 20who may seek out or avoid pyrethrum containing plants depending on the amount necessary todefend against mites and the amount already consumed by the bees,which in higher doses could be potentially toxic to them.This hypothesis can best be tested by a trial wherein a small number of commercial honey25bee colonies are offered a number of pyrethrum producing plants,as well as a typical bee foodsource such as clover,while controls are offered only the clover.Mites could then be introduced to each hive with note made as to the choice of the bees,and the effects of the mite parasites on the experimental colonies versus control colonies.It might be beneficial to test wild-type honey bee colonies in this manner as well,in case there could be some genetic difference between them that affects the bees’preferences for30pyrethrum producing flowers.42、How do the words“can,”“may,”and“could”in the third paragraph(lines11-23) help establish the tone of the paragraph?A)They create an optimistic tone that makes clear the authors are hopeful about the effects of their research on colony collapse disorder.B)They create a dubious tone that makes clear the authors do not have confidence in the usefulness of the research described.C)They create a tentative tone that makes clear the authors suspect but do not know that their hypothesis is correct.D)They create a critical tone that makes clear the authors are skeptical of claims that pyrethrums are inherent in mono-crops.正确答案:C分析:文章当中,作者讨论蜂群问题时,使用了“我们猜想”(we suspect)和“我们推测”(we postulate)这样的句式,还采用了“can””may”和“could”这样表示可能的情态动词,是为了强调作者是猜测但是不确定的语气。43、In line13,the authors state that a certain hypothesis“can best be tested by a trial.”Based on the passage,which of the following is a hypothesis the authors suggest be tested in a trial?A)Honeybees that are exposed to both pyrethrums and mites are likely to develop a secondary infection by a virus,a bacterium,or a fungus.B)Beekeepers who feed their honeybee colonies a diet of a single crop need to increase the use of insecticides to prevent mite infestations.C)A honeybee diet that includes pyrethrums results in honeybee colonies that are more resistant to mite infestations.D)Humans are more susceptible to varroa mites as a result of consuming nutritionally deficient food crops.正确答案:C分析:文章13-16行,作者推测如果蜂群不食用除虫菊,那么他们对螨虫感人没有抵抗力。24-26行中,作者就建议设计一个实验,给一小部分商业蜂群提供大量除虫菊来验证这个推测。44、Which choice provides the best evidence for the answer to the previous question?A)Lines2-3(“These mites...viruses”)B)Lines9-10(“In fact...cream”)C)Lines11-12(“We suspect...deficient”)D)Lines13-16(“Without...bees”)正确答案:D分析:见第43题解释。45、The passage most strongly suggests that beekeepers’attempts to fight mite infestations with commercially produced insecticides have what unintentional effect?A)They increase certain mite populations.B)They kill some beneficial forms of bacteria.C)They destroy bees’primary food source.D)They further harm the health of some bees.正确答案:D分析:文章当中作者提到:当蜂农使用商业杀虫剂时,他们会到导致蜂群免疫功能不全、营养匮乏(immunocompromised or nutritionally deficient).46、Which choice provides the best evidence for the answer to the previous question?A)Lines1-2(“Honey bees...mites”)B)Lines3-4(“Little...control”)C)Lines17-19(“In addition...infestation”)D)Lines26-28(“Mites...control colonies”)正确答案:C分析:见第45题解释。47、As used in line19,“postulate”most nearly means toA)make an unfounded assumption.B)put forth an idea or claim.C)question a belief or theory.D)conclude based on firm evidence.正确答案:B分析:此处postulate的含义是提出一种观点。48、The main purpose of the fourth paragraph(lines24-28)is toA)summarize the results of an experiment that confirmed the authors’hypothesis about the role of clover in the diets of wild-type honeybees.B)propose an experiment to investigate how different diets affect commercial honeybee colonies’susceptibility to mite infestations.C)provide a comparative nutritional analysis of the honey produced by the experimental colonies and by the control colonies.D)predict the most likely outcome of an unfinished experiment summarized in the third paragraph(lines19-41).正确答案:B分析:第四段中作者设计一个实验检测除虫菊能否帮助蜂群抵御螨虫感染。实验中,作者为两组蜂群提供两种不同的食物,一组提供除虫菊,另一组提供普通苜蓿,然后观察两组蜂群对螨虫感染的抵抗能力。49、An unstated assumption made by the authors about clover is that the plantsA)do not produce pyrethrums.B)are members of the Chrysanthemum genus.C)are usually located near wild-type honeybee colonies.D)will not be a good food source for honeybees in the control colonies.正确答案:A分析:在实验中,一组喂食除虫菊,另一组喂食普通苜蓿;两组食物是对比的关系,所以普通苜蓿肯定不会产生除虫菊。50、Based on data in the table,in what percent of colonies with colony collapse disorder were the honeybees infected by all four pathogens?A)0percentB)77percentC)83percentD)100percent正确答案:B分析:表格显示:在右蜂群崩溃综合症的蜂群中,有77%的比例被四种病原体感染。51、Based on data in the table,which of the four pathogens infected the highest percentage of honeybee colonies without colony collapse disorder?A)IAPVB)KBVC)Nosema apisD)Nosema ceranae正确答案:D分析:表格显示:在没有蜂群崩溃综合症的蜂群中,有81%的比例被Nose ceranae感染。52、Do the data in the table provide support for the authors’claim that infection with varroa mites increases a honeybee’s susceptibility to secondary infections?A)Yes,because the data provide evidence that infection with a pathogen caused the colonies to undergo colony collapse disorder.B)Yes,because for each pathogen,the percent of colonies infected is greater for colonies with colony collapse disorder than for colonies without colony collapse disorder.C)No,because the data do not provide evidence about bacteria as a cause of colony collapse disorder.D)No,because the data do not indicate whether the honeybees had been infected with mites.正确答案:D分析:表格显示了感染病原体的蜂群比例,但是没有任何有关蜂群被螨虫感染的信息。因为没有这些信息,所以也不能得出相关结论。

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