Which of the following most logically completes the passage? Mastitis is an infection of the udder in cows that, although not dangerous, causes them to give poor-quality milk. Most cases of mastitis are caused by the bacterium Staphylococcus aureus, against which antibiotics are ineffective. However, a related bacterium, Staphylococcus simulans, quickly clears up even severe infections of S. aureus simply by displacing the bacteria. S. simulans is nevertheless unlikely to become the preferred treatment for cases of mastitis, since ______.
certain dangerous bacteria that normally cannot take hold can do so in the presence of S. simulan
the current resistance of S. aureus to antibiotics derives in part from a past pattern of overuse of those antibiotics
the milk from cows infected with S. aureus is generally not of such poor quality as to be entirely unusable
careful farming practice can reduce the incidence of mastitis to a minimum
the only symptom of mild cases of mastitis is the deterioration in the quality of the milk produced
作者: genius_fang 时间: 2009-12-10 00:01
谢谢LZ！作者: yuling526 时间: 2009-12-10 00:18
逻辑体选b??作者: Tima2009 时间: 2009-12-10 00:23
同意楼上的作者: genius_fang 时间: 2009-12-10 01:03
这倒逻辑选A吧~certain dangerous bacteria that normally cannot take hold can do so in the presence of S. simulan作者: AllenZX 时间: 2009-12-10 09:18
楼主朋友精神可嘉.. 逻辑选A