Though sucking zinc lozenges has been promoted as a treatment for the common cold, research has revealed no consistent effect.Recently, however, a zinc gel applied nasally has been shown to greatly reduce the duration of colds.Since the gel contains zinc in the same form and concentration as the lozenges, the greater effectiveness of the gel must be due to the fact that cold viruses tend to concentrate in the nose, not the mouth.
Which of the following, if true, most seriously weakens the argument?
A. Experimental subjects who used the zinc gel not only had colds of shorter duration but also had less severe symptoms than did those who used a gel that did not contain zinc.
B. The mechanism by which zinc affects the viruses that cause the common cold has not been conclusively established.
C. To make them palatable, zinc lozenges generally contain other ingredients, such as citric acid, that can interfere with the chemical activity of zinc.
D. No zinc-based cold remedy can have any effect unless it is taken or applied within 48 hours of the initial onset of cold symptoms.
E. Drug-company researchers experimenting with a nasal spray based on zinc have found that it has much the same effect on colds as the gel does.
这个题的A哪里错了啊？！！！
作者: 12711399 时间: 2012-11-10 12:57
conclusion: cold virus must concentrated in nose, because when zinc gel applied to nose heal cold faster a) fewer cold symptoms, when zinc gel applied.
this strongly strengthens the argument, not weaken作者: gracedan 时间: 2012-11-10 15:00
还是没懂啊 A不是说用第二种药的人本身病状就轻么？这样不就削弱了结论么？！作者: cynthia0817 时间: 2012-11-10 16:10
不可以削弱文章的前提，前提里说是zg greatly reduce the duration，这是指的一个降低幅度问题，和duration的基数无关
