premise:zinc lozenges has been promoted as a treatment for the common cold premise:a zinc gel applied nasally has been shown to greatly reduce the duration of colds conlusion: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. 你说得对,evaluate的题目就是要从加强和削弱两个方面考虑.很明显这个argument有提示词:since...这样的话是个典型的 causal reasoning. 要削弱和加强一个causal reasoning的话,一般方法是从"他因"方面考虑. 如果能够排除他因,则加强,如果有他因,则削弱. 回来看题: conclusion建立的联系是 concentration一样,因为进入体内的途径不一样,效果不一样,那么virus所存在的位置就不一样. 但是如果有个他因,说两者包含的zinc的activate 程度不一样,那么就可以削弱结论咯. 所以就是D咯,要是两者的activate程度一样,(排除他因)则对原结论加强.如果程度不一样(引入他因),则削弱~~~  |