博智教育，GMAT培训，每日一题。
指导教师，英吉
Which of the following most logically completes the argument?
Ferber's syndrome, a viral disease that frequently affects cattle, is transmitted to these animals through infected feed. Even though chickens commercially raised for meat are often fed the type of feed identified as the source of infection in cattle, Ferber's syndrome is only rarely observed in chickens. This fact, however, does not indicate that most chickens are immune to the virus that causes Ferber's syndrome, since-------
(A)chickens and cattle are not the only kinds of farm animal that are typically fed the type of feed liable to be contaminated with the virus that causes Ferber's syndrome
(B)Ferber's syndrome has been found in animals that have not been fed the type of feed liable to be contaminated with the virus that can cause the disease
(C)resistance to some infectious organisms such as the virus that causes Ferber's syndrome can be acquired by exposure to a closely related infectious organism
(D)chickens and cattle take more than a year to show symptoms of Ferber's syndrome, and chickens commercially raised for meat, unlike cattle, are generally brought to market during the first year of life
(E)the type of feed liable to be infected with the virus that causes Ferber's syndrome generally constitutes a larger proportion of the diet of commercially raised chickens than of commercially raised cattle
题目分析：文章很简单，就是虽然鸡里面没发现这种病毒但是不能证明鸡对这种病毒是免疫的，问原因。A说还有别的动物，有别的动物和鸡是否对这种病毒免疫有什么关系，杀。B围绕的是哪些没有fed the type of feed的动物谈的，但是原文反复谈的就是fed the type of feed的动物，两者范围完全没关系，杀。C说对于某些病毒的resistance需要暴露一些生物才能获得，这个和鸡是否免疫没什么关系。D说这两种动物得病只有需要多余一年才有发病症状，可是鸡一般头一年就被卖了，因为还没发现就被卖了，所以不能证明鸡没有得病，比较顺，留着。E说喂鸡的包含了更大比列的diet比喂牛的，那个比例更大，没提，杀。
