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•29. GWD28-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?
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.
我觉得是B 重点在于理解however, and chickens commercially raised for meat, unlike cattle, are generally brought to market during their first year of life. 鸡不像牛，（鸡）不到一年就被卖了 而鸡少有被确诊得病的，不是因为鸡没感染，而是显示症状之前就被卖了。 如果能在出现症状前发现鸡得病了，那么就不会得出上文观察到的现象“牛确诊，鸡少有” 总觉得这题的逻辑在哪见过... | 
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发表于 2009-8-27 17:00:00
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