求解一道传染病与疫苗的防治问题

Helloface

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.
求助答案为何是E?我选的A~~~~~~~
选E是因为气候不好导致传染病蔓延么？？那A明确说蚊子传播了呀，虽然最后的杀虫剂或许有些无关，但是E也没有明确说气候环境导致传染病爆发后还有继续~~~想不清楚了- -

Carrie2009

我觉得A不好，因为A说杀虫剂impractical, 不等于vaccination就practical。
B 的unaffected countries 与题目无关
C 本题与花多久检验vaccine 无关
D 无关
E 虽然看起来也不太好，但是它的“within two to five months” 可以在时间上支持使用vaccine。再者，题中最后说“next few years”，E说“ almost invariably followed”，刚好说明一种常态。

我感觉逻辑题有时候是找一个相对正确的option。

Helloface

谢谢:-)
确实，是找相对正确的，而且不能多想。其实我做的时候也想那个时间的问题了，但是当时还想“2到5个月”明明比“few years”要短啊，结果没选~呵呵~~

Carrie2009

谢谢:-)
确实，是找相对正确的，而且不能多想。其实我做的时候也想那个时间的问题了，但是当时还想“2到5个月”明明比“few years”要短啊，结果没选~呵呵~~

-- by 会员 Helloface (2010/9/27 17:47:13)

Glad that I could help~

sunshengkun666

我觉得这个题的答案应该至少包含WITH A MONTH相关的信息点，因为题干明确说明这种药一月后失效，但为什么还要坚持使用呢，肯定在这个月内发生了什么事，所以~~~~~