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.
In order to evaluate the argument, it would be most helpful to determine which of the following?
? 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.
? In order to evaluate the argument, it would be most helpful to determine which of the following?
Whether zinc is effective only against colds, or also has an effect on other virally caused diseases
Whether there are remedies that do not contain zinc but that, when taken orally, can reduce the duration of colds
Whether people who frequently catch colds have a zinc deficiency
Whether either the zinc gel or the lozenges contain ingredients that have an impact on the activity of the zinc
Whether the zinc gel has an effect on the severity of cold symptoms, as well as on their duration
若D的结果是 they do contain ingredients that have an impact on the activity of the zinc,那么就引入了新的解释变量-ingredients that influence the activity of the zinc,从而削弱了原结论。若结果是they do not contain,可以理解为既没削弱也没加强,也可以理解为通过枪毙掉一个可能他因而更站得住脚,个人对evaluate标准的理解可能不太一样。 B中可能会有歧义的是when taken orally,因为原文中sucking zinc lozenges,zinc gel applied nasally暗示无论zinc lozenges还是zinc gel它们的治愈效果是与服用方式(因此与病毒位置)有关的,但remedies taken orally并没有这种暗示,譬如吃药片的话它的效果可能是自身的成分所致,与口服这个方法没有关系,因此与病毒在什么地方也没有关系。