单选题 1. Even after numerous products made with artificial sweeteners became available, sugar consumption per capita continued to rise. Now manufacturers are introducing fat-free versions of various foods that they claim have the taste and texture of the traditional high-fat versions. Even if the manufacturers' claim is true, given that the availability of sugar-free foods did not reduce sugar consumption, it is unlikely that the availability of these fat-free foods will reduce fat consumption.
Which of the following, if true, most seriously undermines the argument? ______

A、 Several kinds of fat substitute are available to manufacturers, each of which gives a noticeably different taste and texture to products that contain it.
B、 The products made with artificial sweeteners did not taste like products made with sugar.
C、 The foods brought out in sugar-free versions did not generally have reduced levels of fat, but many of the fat-free versions about to be introduced are low in sugar.
D、 People who regularly consume products containing artificial sweeteners are more likely than others to consume fat-free foods.
E、 Not all foods containing fat can be produced in fat-free versions.

【正确答案】 B

【答案解析】 B：原文的论证前提是人工甜味剂可以类比零脂肪食品(即这两种产品的情况一样)，既然蔗糖的消耗并没有因为甜味剂的出现而减少，那么零脂肪食品也不会削弱脂肪的消耗。但是该选项表明，蔗糖的消耗量之所以没有减少，是因为人工甜味剂和蔗糖的口味不一样，然而原文告诉我们零脂肪食品和高脂肪食品的口味和质地都一样，因此人工甜味剂的情况和零脂肪食品的情况并不相同，论证前提被削弱了，属于“直接削弱原因”，正确。
A：该选项只能说明脂肪替代品的多样性，与原文无关，故不选。
C：原文讨论的是人工甜味剂是否可以和零脂肪食品构成类比，该选项在讨论零脂肪食品和无糖食品之间是否会存在互相削弱的情况，与题干无关，故不选。
D：原文讨论的是人工甜味剂是否可以和零脂肪食品构成类比，与购买人工甜味剂的人是否购买零脂肪食品无关。而且，购买零脂肪食品的人也不见得不会购买高脂肪产品，所以这些人对于零脂肪产品的消耗到底能否影响脂肪的消耗是不确定的，故不选。
E：本文与多少食品有零脂肪版本无关，故不选。