B Fever has usually been regarded as a

题目：

B

　　Fever has usually been regarded as a threat to health.However,no one has actually proved that fever is dangerous.This fact attracted the attention of Matthew J.Kluger.Imagining that fever might not be as harmful as it had been supposed,Kluger set up a series of experiments with lizards(蜥蜴).

　　What Kluger and his team did his team did in their first experiment was simple.They put some lizards in a sand-box,one end of which was heated to 44℃,while the other was at a room temperature.It was found that the lizards moved form one part of the box to the other in order to keep a constant temperature of about 38℃.Having shown that normal lizards regulate(调节) their own temperature,Kuger,in a second experiment,then set out to show that lizards,like most other animals,develop fever when infected.This was done by making lizards infected with bacteria (细菌) that were known to cause disease.As the team expected,the infected lizards remained longer in the heated part of the box,until they had raised their body temperatures to two or three degrees above normal.In other words,the sick lizards gave themselves fever.

　　In a third experiment,the team observed the effect of temperature on the survival of the lizards.One group of infected lizards was given a fever - suppressing(退烧) drug.The other group was given no drug and ran a fever,that is to say,they kept a highter temperature for four or five days before seeking a cooler environment.The results were impressive.Of those which raised their body temperature,all but one remained alive.Of those given the fever - suppressing drug,more than half died.Similar results have since been produced in other animals.For example,infeced fish swim to warmer water,and will die if not allowed to do so.

　　An important conclusion can be drawn from these experiments.As Kluger points out,lizards have been on earth for hundreds of millions of years.It is reasonable to suppose that a response that is so old has been kept by nature for some purpose.It would appear, therefore, that fever does not make disease worse.Rather it its part of the mechanism(机能) by which infection is controlled.

　　60.In his experiments,Kluger was hoping to prove that fever ________.

　　　A.is not harmful to lizards

　　　B.is not necessarily bad

　　　C.is necessary for both humans and animals

　　　D.has the same effect on humans and animals

　　61.The lizards put in the sand - box in the first experiment _____.

　　　A.had a fever B.were not sick C.recovered from disease D.died of heat

　　62.In the third experiment,the lizards given a fever - suppressing drug died because _____.

　　　A.they had no more fever that they needed

　　　B.they were normal ones and had no fever

　　　C.the drug had no iffect on sick lizards

　　　D.the drug made their body temperature too low

　　63.How would you understand the underlined words"a response" in the last paragraph?

　　　A.Gause of disease. B.Recovery from disease.

　　　C.Relationship between living D.Natural defense in the body against disease.