裸机一道~求解惑~

BlackTTea

Until mow,only injectable vaccines against influenza have been available.  arents are reluctant to subject children tothe pain of injections, but adults, who are at risk of serious complicationsfrom influenza, are commonly vaccinated. A new influenza vaccine, administered painlessly in a nasal spray, is effectivefor children.  However, since childrenseldom develop serious complications from influenza, no significant publichealth benefit would result from widespread vaccination of children using thenasal spray.
Which ofthe following is an assumption on which the argument depends?

A.   Any person who has received the injectablevaccine can safely receive the nasal-spray vaccine as well.
B.   The new vaccine uses the same mechanism toward off influenza as jnjectable vaccines do.
C.   The injectable vaccine is affordable for alladults.
D.   Adults do not contract influenza primarilyfrom children who have influenza.
E.    The nasal spray vaccine is mot effectivewhen administered to adults.


答案选D，不是很理解。。。

fujianaicd

原题是：
Premise1: 到现在为止只有注射型的疫苗，家长不愿给小孩打（太痛）
Premise2: 高危（很可能得病）成人常常打针
Premise3: 新研制了一种喷雾型疫苗发现对小孩很有效

Premise4: 由于小孩基本上得病后不会太严重
Coclusion: 使用这种喷雾疫苗不会有明显的医疗好处

做假设，先取反，D取反为：成人主要从小孩那感染疾病。
严重消弱了命题，因此，D对！

BlackTTea

原来是这样~懂了。。谢谢ls~