GWD28-29谢谢拉

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.

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

1. The virus that causes Lofgren’s disease cannot be transmitted to human beings by chickens.
2. 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.
3. 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.
4. 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

C错，因为原题并未推出chickens are immue to the virus that causes this diease 的讯息或结论，因此跟原题无关！因此選C的人犯了一個嚴重的錯誤，就是自行假設！

而B对，因为原题第一句告诉我们Lofgren's disease has beenobserved frequentlyin commercially raisde cattle byt very rarely in chickens说明牛比鸡更常被发现淂了这种疾病，

B正好说明了因为在症状发生前不能判定是否有得到这种疾病，而鸡通常在出生后一年内也就是在症状发生前就被宰杀了，因此B刚好支持了原题所给的"information"

我有一个疑问：

原文只有提出imformation：Lofgren's disease has been observed frequentlyin 

 commercially raisde cattle byt very rarely in chickens 只说出鸡很少被发现得了这种

 疾病，只有提出事实而并没有提出过任何结论或看法，作答的时候是不是不应该加入自己的揣测？

不能加入自己的揣测。

没有提供结论的原因是这题是个归纳题。是要你用所给的信息做出推断。

多谢楼上NN的回复！

我弄错题目意思了，答案应该还是C