标题: 请教一道逻辑题目 [打印本页] 作者: soupset 时间: 2009-11-14 15:10 标题: 请教一道逻辑题目 Which of the following most logically completes the argument?
Although the pesticide TDX has been widely used by fruit growers since the early 1960’s, a regulation in force since 1960 has prohibite d sale of fruit on which any TDX residue can be detected. That regulation is about to be replaced by one that allows sale of fruit on which trace amounts of TDX residue are detected. In fact, however, the change will not allow more TDX on fruit than was allowed in the 1960’s, because ______.
A. pre-1970 techniques for detecting TDX residue could detect it only when it was present on fruit in more than the trace amounts allowed by the new regulations
B. many more people today than in the 1960’s habitually purchase and eat fruit without making an effort to clean residues off the fruit
C. people today do not individually consume any more pieces of fruit, on average, than did the people in the 1960’s
D. at least a small fraction of the fruit sold each year since the early 1960’s has had on it greater levels of TDX than the regulation allows
E. the presence of TDX on fruit in greater than trace amounts has not been shown to cause any harm even to children who eat large amounts of fruit
不袋明白意思。。。觉得A说能检测出来的，是超过规定的量才能检测出来，那怎么the change will not allow more TDX on fruit than was allowed in the 1960’s。。。。超过规定的量，那就不allow啊。。。但是A是答案。。。
C肯定是不对的。如果人吃的比1960年代少，危害就没那么大了。作者: leadwest 时间: 2009-11-22 19:58
A. pre-1970 techniques for detecting TDX residue could detect it only when it was present on fruit in more than the trace amounts allowed by the new regulations 解释：1960法规禁止TDX被检测出，而不是说水果上绝对不含有TDX，有可能检测合格的水果含有微量的TDX。 A选项说，能被1970年前的检测技术能检测出的TDX含量是被新法规禁止的。也就是说，新法规和旧法规一样严格。
B. many more people today than in the 1960’s habitually purchase and eat fruit without making an effort to clean residues off the fruit 诉诸公众意见，排除。 C. people today do not individually consume any more pieces of fruit, on average, than did the people in the 1960’s 过去和现在的人消费水果的数量？ 这是无关比较，排除。 D. at least a small fraction of the fruit sold each year since the early 1960’s has had on it greater levels of TDX than the regulation allows sold each year不代表allowed by the regulation
E. the presence of TDX on fruit in greater than trace amounts has not been shown to cause any harm even to children who eat large amounts of fruit 对人体有害无害？原文结论讨论法规对TDX含量的限制，因此这也是无关选项。排除。