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  3. Running a lever was once thought to be the prerogative of warm-blooded creatures, whose internal temperatures are independent of

Running a lever was once thought to be the prerogative of warm-blooded creatures, whose internal temperatures are independent of

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问题     Running a lever was once thought to be the prerogative of warm-blooded creatures, whose internal temperatures are independent of the weather. But, as Matthew Kluger reported in "The Importance of Being Feverish" (January 1976), lizards can also develop fevers, even though there is no question that they are cold-blooded. They raise their temperatures by moving into the sun or, in the case of Kluger’s experiments, under a sun lamp. And it seems to do them some good. Sick lizards kept in cages at feverish temperatures fare much better than their counterparts in normal mid cool environments.
    Now, fever has spread to invertebrates(无脊椎动物). Recent studies have shown that crayfish and scorpions can develop fevers. Crayfish injected with bacteria and scorpions injected with prostaglandins(前列腺素) swam and scuttled to hot areas. (Prostaglandins are hormones thought to be instrumental in the development of a fever. )
    Evidence is also mounting that moderate fevers have their benefits, which might explain why the fever process is so widespread. Leukocytes, white blood cells that are active in fighting bacterial infections, are more mobile at febrile temperatures. And fevers reduce the amount of iron available to bacteria. That reduction, combined with high temperatures, has been shown to inhibit bacterial growth.
Which of the following best states the main idea of the passage?
选项 A、Cold-blooded animals can develop fevers.
B、There are benefits to developing fevers.
C、Fevers inhibit bacterial growth.
D、Lizards can develop fevers.
答案A
解析 这篇文章的主要内容。文章第一段就给予了说明：Running a fever was once thought to be the prerogative of warm-blooded creatures，...(升高体温曾被认为是热血动物的特权)。但是lizards can also develop fevers，even though there is no question that they are cold-blooded．(蜥蜴也能升高体温，尽管他们毫无疑问属于冷血动物。)随后作者进一步说明，
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