Lofgren's disease has been observed frequently in commercially raised cattle but very rarely in chic...

题目信息

Lofgren's disease has been observed frequently in commercially raised cattle but very rarely in chickens. Both cattle and chickens raised for meat are often fed the type of feed that transmits the virus that causes the disease. Animals infected with the virus take more than a year to develop symptoms of Lofgren's disease, however, and chickens commercially raised for meat, unlike cattle, are generally brought to market during their first year of life.

Which of the following is most strongly supported by the information provided?

A:The virus that causes Lofgren's disease cannot be transmitted to human beings by chickens.

B:There is no way to determine whether a chicken is infected with the Lofgren's disease virus before the chicken shows symptoms of the disease.

C:A failure to observe Lofgren's disease in commercial chicken populations is not good evidence that chickens are immune to the virus that causes this disease.

D:An animal that has been infected with the virus that causes Lofgren's disease but that has not developed symptoms cannot transmit the disease to an uninfected animal of the same species.

E:The feed that chickens and cattle are fed is probably not the only source of the virus that causes Lofgren's disease.

参考答案及共享解析

共享解析来源为网络权威资源、GMAT高分考生等；如有疑问，欢迎在评论区提问与讨论

正确答案： C:A failure to observe Lofgren's disease in commercial chicken populations is not good evidence that chickens are immune to the virus that causes this disease.

背景：L病在肉牛上很常见，但是在肉鸡上不常被发现；文章中的信息有三个：1.肉鸡和肉牛都经常被喂食带有病毒并且会致病的饲料；2.感染了L病病毒的动物经常要一年多才会发病；3.肉鸡总是不到一年就被宰了，所以自然就可以得出，没有发现肉鸡发病并不能说明肉鸡就没有染病

问的是一个conclusion supported by the information above 是一道总结归纳题

通过原文得出 C正确. 错误的判断鸡没有感染并不能说明鸡对这种致病病毒免疫

笔记