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标题: ＧＷＤ１６－３８，没找到哦 [打印本页]

作者: Jolin_hz 时间: 2007-4-29 15:08
标题: ＧＷＤ１６－３８，没找到哦

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.

Answer: E

请教为什么是Ｅ，Ｅ说的是within two to five months，题干说within the next few years.．

作者: joy110211 时间: 2007-4-29 16:58

E的意思是說, 每次這個fever出現後的2~5個月內都有氣候變化. 這個想法是說氣候變化會造成更多cattle死亡, 所以雖然價錢貴, 農夫們還是會使用疫苗, 希望能將死亡降至最低.

如果我解釋的不夠清楚或是思路不對, 請NN幫忙.

作者: gonghao 时间: 2007-4-30 12:00
气候的可侦测性使得预防fever成为可能，因为一旦某种天气出现，随后必然后有爆发fever

作者: 王一兔 时间: 2007-9-14 20:49

我觉得是这个意思：identificable climate change followed by 牛fever，说明只要一监测到气候变化，2——5个月后就会有牛生病。文章说，以前不用那个注射剂是因为牛发病一个月以后才会有效。而现在，只要气候一变，就可以给牛注射，因为2-5个月后牛肯定会生病，这样的话正好提早一个月注射，等牛要生病的时候药效正好发挥作用。

题目focus的就是为什莫本来注射剂不被采纳，而气候监测结果出来后就能采用注射剂的方法了。要把重点放在注射剂原来的缺点被解决了。

想了好久，觉得自己想对了。不知道大家能不能明白我不够精准的描述。

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