Day 24 A recently issued twenty-year study on headaches suffered by the residents of Mentia investigated the possible therapeutic effect of consuming salicylates

A recently issued twenty-year study on headaches suffered by the residents of Mentia investigated the possible therapeutic effect of consuming salicylates. Salicylates are members of the same chemical family as aspirin, a medicine used to treat headaches. Although many foods are naturally rich in salicylates, food-processing companies also add salicylates to foods as preservatives. The twenty-year study found a correlation between the rise in the commercial use of salicylates and a steady decline in the average number of headaches reported by study participants. At the time when the study concluded, food-processing companies had just discovered that salicylates can also be used as flavor additives for foods, and, as a result, many companies plan to do so. Based on these study results, some health experts predict that residents of Mentia will suffer even fewer headaches in the future.

Write a response in which you discuss what questions would need to be answered in order to decide whether the prediction and the argument on which it is based are reasonable. Be sure to explain how the answers to these questions would help to evaluate the prediction.

五问：

（1）“A recently issued twenty-year study on headaches suffered by the residents of Mentia investigated the possible therapeutic effect of consuming salicylates. Salicylates are members of the same chemical family as aspirin, a medicine used to treat headaches. Although many foods are naturally rich in salicylates, food-processing companies also add salicylates to foods as preservatives. The twenty-year study found a correlation between the rise in the commercial use of salicylates and a steady decline in the average number of headaches reported by study participants. At the time when the study concluded, food-processing companies had just discovered that salicylates can also be used as flavor additives for foods, and, as a result, many companies plan to do so”是事实，“some health experts predict that residents of Mentia will suffer even fewer headaches in the future”是结论，值得反驳吗？

（2）长达 20年的研究时间足够长吗？文章里是否提供了充分的背景知识让我们判定这个时间长度是否足够？其他相应的信息充足吗？

（3）商业上使用水杨酸的方式可能有哪些？一定是作为食品添加剂被人们吃下去吗？如果还有其他非食用性的商业用途，原文的结论是否还能成立呢？水杨酸还可用于化妆品、防腐剂、消毒剂等，这些与治疗头痛均无关系。

（4）原文中指出，报告头疼的实验参与者直线减少，但文中是否给出了详细的信息，确定这些参与者具有足够的代表性？你能说说其他的可能性吗？例如：体质差异、年龄差异等。另外，报告头疼的实验参与者人数持续减少一定是因为水杨酸的商业使用增加吗？还有其他因素吗？例如：环境改善了，实验参与者加强了身体锻炼、体质增强了，或者服用了其他治疗头疼的药物。

（5）原文只给出信息说水杨酸能够减缓头疼，但水杨酸的有效性在微量与巨量之间是否可能并没有大的差异？更何况原文中并没有强调所有的公司都将这样做。另外，原文中是否强调了这些公司都会专门针对当地采取特定的策略？这会怎样影响原文论述的有效性？如果添加水杨酸的食品并不受 Mentia当地人欢迎，那么居民摄入的水杨酸不一定会增多，头痛症状也不一定会减少。