GRE阅读无忧系列之练习(七)-智课教育旗下智课教育.pdf

智 课 网 G R E 备 考 资 料 GRE阅读无忧系列之练习(七)-智课教育旗下智课教育 对于GRE阅读，想要取得高分的唯一捷径就是多做练习题，熟能生 巧，在考场上才能得心应手。尽于此，智课教育推出GRE阅读无忧系列 之练习，帮助大家更好地备考。 以下是GRE阅读无忧系列之练习(七)，里面是智课教育小编精心整 理的文章等级为medium的练习题，每个练习题有答案和解析，希望能 够助考生取得GRE阅读高分。 Warm-blooded animals have elaboratephysiological controls to maintain constant body temperature (in humans, 37℃). Why then during sickness shouldtemperature rise, apparently increasing stress on the infected organism? It haslong been known that the level of serum iron in animals falls during infection.Garibaldi first suggested a relationship between fever and iron. He found thatmicrobial synthesis of siderophores—substances thatbind iron—in bacteria of the genus Salmonella declinedat environmental temperatures above 37℃ and stopped at40.3℃. Thus, fever would make it more difficult for aninfecting bacterium to acquire iron and thus to multiply. Cold-blooded animalswere used to test this hypothesis because their body temperature can becontrolled in the laboratory. Kluger reported that of iguanas infected with thepotentially lethal bacterium A. hydrophilia, more survived at temperatures of42℃ than at 37℃, even though healthy animals prefer the lower temperature. When animals at 42℃ were injected with an iron solution, however, mortality rates increased significantly. Research to determine whether similar phenomena occur in warm-blooded animals is sorely needed. 1. The passage is primarily concerned with attempts to determine (A) the role of siderophores in the synthesis ofserum iron (B) new treatments for infections that arecaused by A. hydrophilia (C) the function of fever in warm-bloodedanimals (D) the mechanisms that ensure constant bodytemperature (E) iron utilization in cold-blooded animals 2. According to the passage, Garibaldi determined which of the following? (A) That serum iron is produced throughmicrobial synthesis. (B) That microbial synthesis of sideroph