gwd-12-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?

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

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

3. 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.

4. 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

   我选的是C，可答案是E。 这和气候有什么关系？？实在不懂。哪位高人指点下吧~~谢谢啦。。。

RV热这个病爆发会导致数千牛死亡。有疫苗但是基本不用，因为贵，而且一个月才有效，所以其帮助甚微。
但是专家预计疫苗的使用会在几年内暴涨。问加强

A. 蚊子的传播范围大没法控制。这至少没说未来几年和前几年有什么区别，没有导致增加疫苗使用的理由。

B. 其他国家不进口。但是不知道这个国家的牛主要是自产自销还是出口用，缺条件，没有导致增加疫苗使用的理由。

C. 一个月内制造商就能通过调整增产疫苗。但是增产并不意味着使用增加。概念偷换。

D. 很难获得疫苗，那更不能增加使用了，效果相反。

E. RV热总是在特定气候环境下2-5月内发生。使得疫情发生可以预知，从而为针对性的投放疫苗打下基础。发出这个疫情信息会促使人去给牛做免疫处理。是可能增加疫苗使用的。

呵呵，不知道解释的对不对。

这里的Ｃ说了ｉｎｃｒｅａｓｅ　ｉｎ　ｄｅｍａｎｄ呀　这不就说明使用会增加吗？？

哎 我的逻辑啊 我感觉我没有西方人的思维~  完了我的考试啊

E的一个问题在于，E选项说疾病在未来2到5个月会爆发，而题目的结论是未来几年对疫苗的使用都会增加。如何从未来5个月推到未来几年？完全没有理由啊，这是我排除E的理由。

看来看去，只能选D

这位童鞋，D哪里说到很难获得疫苗了，D说的是很难获得modern veterinary medicine。而且D说这些农民遭受热病的打击最大，所以这两个因素迫使他们要去购买疫苗。选D
        

Open to discussion.