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

Running a fever 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 fever 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 and 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.
Scorpions injected with prostaglandins move to hot areas to ______.
选项 A、engage in greater activity
B、seek out a more iron environment
C、demonstrate that they are ill
D、develop a fever and fight bacterial infections
答案D
解析 文章最后一段提到发烧是有一定好处的，可以抵御细菌的增长。因此，D 为正确选项。 A “从事更为剧烈的活动”；B “寻找更为严酷的环境”；C “显示他们病了”均不对。
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