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标题: GWD16——38 [打印本页]

作者: pandaeyes 时间: 2007-5-31 00:52
标题: GWD16——38

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?

Rift Valley fever is spread by mosquitoes, but each outbreak is so widespread that it is impractical to control it by using insecticides.
When an outbreak of Rift Valley fever occurs, unaffected countries often refuse to import livestock from the countries affected by the outbreak.
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.
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.
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.（理解：虽然一个月之后才有效helps a little，但使用了它可以避免一个月之后的气候的变化///可是题中并没有词表明climatic conditions是不好的啊，难道是identifiable?）

作者: ivysopher 时间: 2007-5-31 16:49

为什么c不对？experts predict that use of the vaccine will increase significantly within the next few years

E 怎么去justify 这个next few years呢？所以我认为只有vaccine本身变得能对outbreak有效了才会有significantly increase in the next few years;

个人意见和lz探讨

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