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 prohibited 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 ______.
英文解释:The argument says that even though the pesticide law has become more lenient (from no TDX to traces of TDX being allowed) the amount of TDX on fruits will be the same as was allowed in the 60s. You have to explain how this will be the case?The problem is that you are starting with the assumption that there was No TDX residue in the 60s but now that the law has become lenient why shouldn't there be any residue? But just think what if there actually was TDX residue (as per option 1) on fruits in the 60s but could not be detected by the authorities?The authorities would have thought there was no residue while there actually was some residue and according to Option A this residue is the same (in terms of quantity) as the traces that have been allowed by the change to the Regulation now.Hence its perfectly possible that, even though the Regulation has become more lenient, the actual amount of TDX present on fruits remains the same.
原先的假设是只要检测出来有TDX就不能卖,而现在条件放宽到可以有含小于等于trace amounts的量也可以卖——但是,现在的问题是检测设备在小于量x的情况下检测不到TDX,而这个x如果大于等于trace amounts,则新的regulation有没有都没用,即因为检测不到,早就卖含有trace amounts量的水果了