 Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researchers believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Researchers hypothesize that
this vaccine was the source of the virus found in mesotheliomas decades later.
Which of the following, if true, most strongly supports the researchers’ hypothesis?
A. SV40 is widely used as a research tool in cancer laboratories. B. Changes in the technique of manufacturing the vaccine now prevent contamination with SV40. C. Recently discovered samples of the vaccine dating from 1960 still show traces of the virus. D. In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos. E. In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40. 虽然暴露在石棉中是导致M病（一种慢性癌）的主要原因，研究者相信感染了S病毒才是主要原因。因为在美国，M病的60%细胞样本中包括S病毒，但没有一个来自健康的细胞。S病毒是猴子身上的一种病毒，但在1960年一些P疫苗被S病毒污染了。 研究者推断：这些感染于1960年的疫苗是十年后在M病中被发现的。 Answer:
其实有人选E的原因在于误认为结论是：疫苗的病毒导致了M病的病毒。其实结论应该是：60年疫苗的病毒就是10年后M病的病毒。请体会这两者的区别。前者强调的是因果关系，后者强调的是这种病毒一直存在着。这是基于这个原因，C才对，因为C强调的正是这种病毒一直存在着。 拉拉思路：感觉选项中应该有年代 E不能成为答案！ researchs' hypothesis是被污染的疫苗是virus的源头， C说，最近发现被污染的疫苗确实是源头，从而支持了研究人员先前的猜测。 E说，在芬兰，没有被污染的疫苗不是virus的源头。这跟researchs'hypothesis无关， 1。我原来之所以选E，因为文章只提到研究发现的现象，并不能说明是由于sv 造成的。（og里有个例子说经过调查，作息时间导致夫妻不和，其削弱就是实际上是夫妻不和导致作息不一致。）对于这题来说就是M导致了sv还是sv导致了M呢？而E选项支持了sv导致M这样一个因果关系。但是大家忽略了这句话sv是猴子病毒，隐含的意思就是正常人体没有sv，于是否定了M导致了sv。 2。正如前人说的结论是Researchers hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later. 其实文章本来就sv是根源了，而研究人员假设是decades later 的根源，那就只能c才说的通了。 倾向于C 有点长,希望大家耐心看下去 开始我坚定的选E,看了大家的讨论之后倾向于C了,下面说说我的看法,灵感来源于lawyer: 文中的hypthesis是说感染了病毒的疫苗是在这之后几十年里从肿瘤的组织上发现这种病毒的根源. 那么当时60年疫苗中的病毒一定能感染人,注意:病毒感染人和感染疫苗是不一样的,可能病毒在污染了疫苗之后就死掉了(现实中完全可能),那么虽然疫苗被污染,但是人却没有感染这种病毒的可能性,所以要加强假设:疫苗中的病毒具有感染性,也就是疫苗中的病毒还存活着,也就是C,我认为关键是在病毒污染了疫苗并且还是疫苗中存活 而E是finland的疫苗没被病毒污染,所以在肿瘤中没发现病毒,这也不足以说明被病毒污染了的疫苗,那么就会在肿瘤中发现病毒,中间缺一个桥梁,那就是疫苗中的病毒存活,才有感染性 例如:我说我得了感冒,并且我接触的人中有人得感冒,那么研究者的假设是:我所接触的患感冒的人是我得感冒的根源. E选项:接触的人没患感冒,所以得不了感冒(不足以说明我接触了感冒患者就会得感冒,因为可能我接触的感冒患者患的感冒是不传染的,我得感冒另有他因) C选项:我所接触的患感冒的人至今还有传染别人的能力(我被传染的可能性大了,支持了研究者的假设) 结论：疫苗是后来数十年癌症中某种病毒的来源
C：
最近发现的60年代的疫苗中仍有该病毒的踪迹
1. 从字面上看，C中根本没有提到癌症的事，按理说是无法加强结论的
2. 深入分析，结论说是癌症中的病毒的来源，C仅仅说疫苗中有病毒（并且这在文中都是已知了in 1960 some polio vaccine was contaminated with the virus），并没能加强癌症中的这种病毒是从疫苗中来的
E: 疫苗没受感染，则癌症中就没有这种病毒
多好的加强啊！正说明癌症中的这种病毒就是从疫苗里来的E ------------------------------------------------------------------------------------------------------------ Yeasts capable of leavening bread are widespread, and in the many centuries during which the ancient Egyptians made only unleavened bread, such yeasts must frequently have been mixed into bread doughs accidentally. The Egyptians, however, did not discover leavened bread until about 3000 B.C. That discovery roughly coincided with the introduction of a wheat variety that was preferable to previous varieties because its edible kernel could be removed from the husk without first toasting the grain.
Which of the following, if true, provides the strongest evidence that the two developments were causally related?
A. Even after the ancient Egyptians discovered leavened bread and the techniques for reliably producing it were well known, unleavened bread continued to be widely consumed.无关 B. Only when the Egyptians stopped the practice of toasting grain were their stonelined grain-toasting pits available for baking bread. C. Heating a wheat kernel destroys its gluten, a protein that must be present in order for yeast to leaven bread dough. D. The new variety of wheat, which had a more delicate flavor because it was not toasted, was reserved for the consumption of high officials when it first began to be grown.无关 E. Because the husk of the new variety of wheat was more easily removed, flour made from it required less effort to produce. Answer: 拉拉：应该与加热有关without first toasting。
C ------------------------------------------------------------------------------------------------------------ Which of the following most logically completes the argument below?
Although the number of large artificial satellites orbiting the Earth is small compared to the number of small pieces of debris in orbit, the large satellites interfere more seriously with telescope observations because of the strong reflections they produce. Because many of those large satellites have ceased to function, the proposal has recently been made to eliminate interference from nonfunctioning satellites by exploding them in space. This proposal, however, is ill conceived, since _______.
A. many nonfunctioning satellites remain in orbit for years无关 B. for satellites that have ceased to function, repairing them while they are in orbit would be prohibitively expensive无关 C. there are no known previous instances of satellites’ having been exploded on purpose无关 D. the only way to make telescope observations without any interference from debris in orbit is to use telescopes launched into extremely high orbits around the Earth与结论矛盾，结论说困难，这里说可能。 E. a greatly increased number of small particles in Earth’s orbit would result in a blanket of reflections that would make certain valuable telescope observations impossible
Editorial: An arrest made by a Midville police officer is provisional until the officer has taken the suspect to the police station and the watch commander has officially approved the arrest. Such approval is denied if the commander judges that the evidence on which the provisional arrest is based is insufficient. A government efficiency expert has found that almost all provisional arrests meet standards for adequacy of evidence that watch commanders enforce. The expert therefore recommends that the watch commander’s approval should no longer be required since the officers’ time spent obtaining approval is largely wasted. This recommendation should be rejected as dangerous, however, since there is no assurance that the watch commanders’ standards will continue to be observed once approval is no longer required.
In the editorial, the two portions in boldface play which of the following roles?
A. The first is a recommendation made by the editorial; the second acknowledges a potential objection against that recommendation.不对。 B. The first is a proposal against which the editorial is directed; the second is a judgment reached by the editorial concerning that proposal.建议 C. The first provides evidence in support of a recommendation that the editorial supports; the second is the conclusion reached by the editorial.不对 D. The first is a position that the editorial challenges; the second is a judgment that was made in support of that challenged position. E. The first is a recommendation that the editorial questions; the second provides evidence against that recommendation.不是 Answer:
B：The first is a proposal which the editorial is directed against.第一个是社论反对的一个提议； the second is a judgment reached by the editorial concerning that proposal.第二个是社论基于那个提议而提出的判断 第二个还是对第一个作出的评价，而不是新的。B ------------------------------------------------------------------------------------------------------------ Which of the following most logically completes the passage?
A certain tropical island received food donations in the form of powdered milk for distribution to its poorest residents, who were thought to be malnourished. Subsequently, the rate of liver cancers among those islanders increased sharply. The donated milk was probably to blame: recent laboratory research on rats has shown that rats briefly暂时 exposed to the substances aflatoxin tend to develop liver cancer when fed casein, a milk protein. This result is relevant because _______.
A. in the tropics, peanuts, a staple of these island residents, support a mold growth that produces aflatoxin B. the liver is more sensitive to carcinogens, of which aflatoxin may be one, than most other bodily organs C. casein is not the only protein contained in milk D. powdered milk is the most appropriate form in which to send milk to a tropical destination E. the people who were given the donated milk had been screened for their ability to digest milk Answer: 拉拉错选为B。AB之间 CDE明显无关 A把两者联系起来，题干说：老鼠吃了A再吃奶，就会得肝癌，而A说当地人吃了富含A的花生，又吃了赞助的奶粉，正好联系起来。而以前没有牛奶，所以病情稳定，现在有了牛奶，一下子爆发了。 错因：个别生词不懂，没仔细A ------------------------------------------------------------------------------------------------------------ Insect infestations in certain cotton-growing regions of the world have caused dramatic increases in the price of cotton on the world market. By contrast, the price of soybeans has long remained stable. Knowing that cotton plants mature quickly, many soybean growers in Ortovia plan to cease growing soybeans and begin raising cotton instead, thereby taking advantage of the high price of cotton to increase their income significantly, at least over the next several years.虚拟：表示价格还没有高。
Which of the following, if true, most seriously weakens the plan’s chances for success?
A. The cost of raising soybeans has increased significantly over the past several years and is expected to continue to climb. B. Tests of a newly developed, inexpensive pesticide have shown it to be both environmentally safe and effective against the insects that have infested cotton crops. C. In the past several years, there has been no sharp increase in the demand for cotton and for goods made out of cotton.前几年情况与后几年无关 D. Few consumers would be willing to pay significantly higher prices for cotton goods than they are now paying. E. The species of insect that has infested cotton plants has never been known to attack soybean plants. Answer:
拉拉错在选了DE，看来没搞懂。DE中都有无关成份。还有一个就是用了常识： 教训：把题看完整，不要想当然 只要需求不上升，价格就不会上升，实际上这个一般规律的东西在本文并没有出现，本文没有说demand results to the rising of the price呀！当然是无关的了。而且D还偷换了概念，把棉花和cotton goods混了，所以即使棉花价格上升，其产品未必涨价，也许劳动力成本提高了。所以D错。 D错在：目前的COTTON价格已经能让棉农能增加他们的收入，目标已能达到。D表达的是人们不愿付比现在高的价格，对目前的价格并不排斥。所以棉农增加收入的目标还是能达到。WEAKEN不了结论。B because of the inexpensive pesticide, the cost of cotton supply goew down, therefor, supply goes up. same demand, more supply, the price goes down. B应该是答案。"虫害导致cotton price increase，然后......"，如果能制止虫害则没有以后的推论了。B正是隐含着这个条件。
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发表于 2007-5-17 16:53:00
