Q29: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. 看逻辑链：牛和鸡都吃带病毒的东西－－－这个病1年后发病，而鸡1年不道就杀了－－－牛得病；鸡不得。
看逻辑链：牛和鸡都吃带病毒的东西－－－这个病1年后发病，而鸡1年不道就杀了－－－牛得病；鸡不得。 看逻辑链：牛和鸡都吃带病毒的东西－－－这个病1年后发病，而鸡1年不道就杀了－－－牛得病；鸡不得。 Which of the following is most strongly supported by the information provided? 问：能得出什么。 逻辑链很清楚，因为鸡1年不到就杀了，所以说鸡不得病（这本身是有缺陷得，因为鸡没到发病期就被杀了）
问：能得出什么。 逻辑链很清楚，因为鸡1年不到就杀了，所以说鸡不得病（这本身是有缺陷得，因为鸡没到发病期就被杀了） 问：能得出什么。 逻辑链很清楚，因为鸡1年不到就杀了，所以说鸡不得病（这本身是有缺陷得，因为鸡没到发病期就被杀了） - The virus that causes Lofgren’s disease cannot be transmitted to human beings by chickens.
- 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.（未发病之前没有办法断定鸡是不是有病，有没有方法可以判断鸡得不得病不是文章得终点，终点在于逻辑推理的缺陷。即，未到发病期就杀了说鸡一定比牛难得这病，是不能接受得。）
- 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.（没有查处记得病不能得出鸡有免疫力，正确，鸡没到发病期就杀了，当然是A failure to observe Lofgren’s disease，这肯定就不能断定说鸡比起牛难得病 ）
- 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.
The feed that chickens and cattle are fed is probably not the only source of the virus that causes Lofgren’s disease. 想不明白B，C有什么区别，谢谢拉 | 
