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2013gre考试预测:4月gre阅读备考机经(5)

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2013-03-28 10:57

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  新gre考试阅读机经:蜜蜂升温

   蜜蜂升温

  Ingestion of food containing spores(孢子) of the pathogen Ascosphaera apis causes a fatal fungal disease known as chalk brood in honeybee larvae. However, larvae must be chilled to about 30°C(normal brood-comb temperature is 33-36°C)for the disease to develop. Accordingly(因此), chalk brood is most common in spring and in small colonies. A recent study revealed that honeybees responsible for hive-temperature maintenance purposely raised the hives’ temperature when colonies were inoculated with A.apis. this “fever,” or up-regulation of temperature, occurred before any larvae died, suggesting that the response is preventative and that either honeybee workers detect the infection before symptoms are visible or larvae communicate the ingestion of the pathogen.  Temperature returned to normal by the end of the study, suggesting that increased temperature is not optimal when broods are not infected, as well as that the fever does not result merely from normal colony growth (i.e., an increase in the number of workers available for temperature maintenance).

  【文章说了一种病原体,简称A病原体.蜜蜂幼虫吃了含有A的食物之后,体内会长一种致命的菌简称CB.但是CB要在低于幼虫正常体温的情况下才会发作,所以CB主要是在春天侵害小规模的蜜蜂群. 最近一个研究发现.在蜂群感染了A之后,那些负责维持蜂房温度的蜜蜂会有意识地提高蜂房温度. 而这个"发烧现象",或者说温度的提升是在没有一个幼虫(因病)死亡之前发生的.(这个现象)可能说明蜜蜂的这一反应(提高温度)是一个保护性措施.而且 (还说明)要么是那些蜜蜂在感染症状出现之前就发现了它们,要么就是幼虫把感染信息告诉了蜜蜂. 实验结束的时候,(蜂房的温度)又恢复正常了,说明升高的温度并不是蜂群的最佳温度,也说明这个"发烧现象"不仅仅是蜂群数量增大的结果.】

  24. The primary purpose of the passage is to

  (A) discuss the findings and implications of a particular study

  (B) illustrate a process that formerly had been misunderstood

  (C) outline the methods used to investigate a problem

  (D) provide evidence to support a controversial theory

  (E) contrast alternative interpretations of certain date

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