himba

1.由题目的写法可知,此题是在考"推论".推论题的特点是,标准答案=原文句子改写. 2.回文章中找寻和modern sanitation有关的句子,发现有二: a. modern sanitation was able to delay exposure to polio until adolescece or adulthood, b. Thus, the hygiene that helped prevent typhoid epidemics indirectly foster a paralytic polio epidemic. 3.抉择:选B句为考量的对象,Thus, the hygiene that helped prevent typhoid epidemics indirectly foster a paralytic polio epidemic. hygiene helped prevent typhoid epidemics → a lack of sanitation → An epidemic of typhoid. 4. D不对，infants无论如何不会病发paralytic polio. (Previously, infection had occurred during infancy, when it typically provided lifelong immunity without paralysis.)