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决胜六级--阅读（4）
1
Running a fever was once thought to be the prerogative of warmblooded creatures, whose internal temperatures are indpendent 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 coldblooded. 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.
1. Which of the following best states the main idea of the passage?
A. Coldblooded animals can develop fevers.
B. There are benefits to developing fevers.
C. Fevers inhibit bacterial growth.
D. Lizards can develop fevers.
2. Fevers cause ____.
A. prostaglandins to be formed
B. iron to be made available to bacteria
C. leukocytes to be more mobile
D. lizards to be coldblooded animals
3. Which of the following statements is true?
A. Developing fever is the privilege of warmblooded animals, so sick lizards can not run a fever.
B. Invertebrates also have the ability to raise their temperature.
C. The internal temperatures of warmblooded creatures are independent of the weather, so are the coldblooded animal.
D. Sick lizards move into the sun to develop fever.
4. The passage implies that ____.
A. the fever process is widespread because moderate fevers have benefits
B. the reduction of fevers can inhibit bacterial growth
C. man can use sun lamp to raise lizards’ temperature
D. Crayfish injected with bacteria have a purpose for moving to hot areas
5. Scorpions injected with prostaglandins move to hot areas to ____.
A. engage in greater activity
B. seek out a moreiron environment
C. demonstrate that they are ill
D. develop a fever and fight bacterial infections
2
In the Caucasus region of the Soviet Union, nearly 50 out of every 100,000 people live to celebrate their 100th birthday, and many don’t stop at 100. By comparison, in America only 3 people in 100,000 reach 100. But these Soviet old people aren’t alone. The Pakistani Hunzas, who live high in the Himalaya Mountains, and the Vilcabambans of the Andes Mountains in Ecuador seem to share the secret of long life too.
These peoples remain healthy in body and spirit despite the passage of time. While many older persons in industrial societies become weak and ill in their 60s and 70s, some Soviet Georgians, aged 110 to 140, work in the fields beside their great greatgrandchildren. Even the idea of aging is foreign to them. When asked, “At what age does youth end?” most of these old people had no answer. Several replied, “Well, perhaps at age 80.” The very youngest estimate was age 60.
What accounts for this ability to survive to such old age, and to survive so well? First of all, hard physical work is a way of life for all of these long lived peoples. They begin their long days of physical labor as children and never seem to
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