OG-119

billgong

D. An epidemic of paralytic polio among infants

D选项中最大的问题是"paralytic"。如果没有这个词，而是"An epidemic of polio among infants"，那么这个选项是对的。因为Line12, "..., when it typically provided lifelong immunity without paralysis"。

实际上，OG中的解释是很精确的，"Choice D is incorrect because, according to lines 10-12, polio in infants does not typically cause paralysis." 只是太简单了一些，不多看几遍不容易搞明白。