GWD1-Q40: ???

GWD1-Q40:

Until mow, only injectable vaccines against influenza have been available.  Parents are reluctant to subject children to the pain of injections, but adults, who are at risk of serious complications from influenza, are commonly vaccinated.  A new influenza vaccine, administered painlessly in a nasal spray, is effective for children.  However, since children seldom develop serious complications from influenza, no significant public health benefit would result from widespread vaccination of children using the nasal spray.

Which of the following is an assumption on which the argument depends?

1. Any person who has received the injectable vaccine can safely receive the nasal-spray vaccine as well.

2. The new vaccine uses the same mechanism to ward off influenza as jnjectable vaccines do.

3. The injectable vaccine is affordable for all adults.

4. Adults do not contract influenza primarily from children who have influenza.

5. The nasal spray vaccine is mot effective when administered to adults.

Why choose D?

Thanks

呵呵,这是数学区,出现逻辑题了哈~~

假设题,对假设取非后会造成原文不成立的后果.原文说,由于儿童很少受该种并发症之苦,所以新疫苗对公共卫生没有太大用处.

答案D,说成人不会主要从发病儿童那儿受到感染.

如果D取非,也就是成人主要从儿童那里被传染,则控制儿童的感染就成了首要之务,这种新疫苗对公共卫生的意义也就很大了.对D的取非造成了原推理不成立.

非常感谢！！！