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标题: GWD-V-12new-38 (XY09) [打印本页]

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作者: luckg    时间: 2006-8-15 12:40
标题: GWD-V-12new-38 (XY09)

 

Q38:

Outbreaks of Rift Valley fever occur irregularly in East Africa, several years apart.  When outbreaks do occur, they kill thousands of cattle.  A livestock vaccine against the disease exists but is rarely used.  It is too expensive for farmers to use routinely, and since it is not effective until a month after vaccination, administering it after an outbreak begins helps very little.  Nevertheless, experts predict that use of the vaccine will increase significantly within the next few years.

 

Which of the following, if true, provides the strongest justification for the experts’ prediction?

 

A.   Rift Valley fever is spread by mosquitoes, but each outbreak is so widespread that it is impractical to control it by using insecticides.

B.   When an outbreak of Rift Valley fever occurs, unaffected countries often refuse to import livestock from the countries affected by the outbreak.

C.   It would take less than a month for producers of the vaccine to adjust their production operations to cope with a large increase in demand.

D.   Many cattle farmers in East Africa are nomadic or live in remote villages, and such farmers, who have little access to modern veterinary medicine, are particularly hard hit by outbreaks of Rift Valley fever.

E.   Recently published research has shown that certain identifiable climatic conditions are almost invariably followed, within two to five months, by an outbreak of Rift Valley fever.

Key is E.

我不明白气候的变化和用疫苗的增长有什么关系？谢谢指导!

Q38:

Outbreaks of Rift Valley fever occur irregularly in East Africa, several years apart.  When outbreaks do occur, they kill thousands of cattle.  A livestock vaccine against the disease exists but is rarely used.  It is too expensive for farmers to use routinely, and since it is not effective until a month after vaccination, administering it after an outbreak begins helps very little.  Nevertheless, experts predict that use of the vaccine will increase significantly within the next few years.

 

Which of the following, if true, provides the strongest justification for the experts’ prediction?

 

A.   Rift Valley fever is spread by mosquitoes, but each outbreak is so widespread that it is impractical to control it by using insecticides.

B.   When an outbreak of Rift Valley fever occurs, unaffected countries often refuse to import livestock from the countries affected by the outbreak.

C.   It would take less than a month for producers of the vaccine to adjust their production operations to cope with a large increase in demand.

D.   Many cattle farmers in East Africa are nomadic or live in remote villages, and such farmers, who have little access to modern veterinary medicine, are particularly hard hit by outbreaks of Rift Valley fever.

E.   Recently published research has shown that certain identifiable climatic conditions are almost invariably followed, within two to five months, by an outbreak of Rift Valley fever.

Key is E.

我不明白气候的变化和用疫苗的增长有什么关系？谢谢指导!

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作者: caterpillarcn    时间: 2006-8-15 13:36

题目中说疫苗不被使用是因为要想产生作用，必须提前一个月注射，而等到病发时在注射，就晚了。
所以这个疫苗的注射是预防性的，而不是针对性的。而它又不便宜，所以没人用他。
但是专家估计下来的几年会有很多人用，说明了有方法可以预测发病期，然后提前注射来预防。

E 某种天气是发病的预示。。。。。。

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