求GWD-5-Q32

ossan

GWD-5-Q32:
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 ______.

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[

为什么是A

cycyang

同意楼上的，这其实是一个数学问题。
60年代：容许的TDX使用量是微量范围以内（虽然规定是禁止有TDX残存，但是当时的技术测量不到）。
现在：新规定中容许的TDX残存也是微量范围以内。

cycyang

如果A为真，则可推断：60年代的TDX农药残存监测技术是检测不出新规定容许范围内的微量TDX的，当时即使有TDX残存，若在微量范围内，视同于没有。因此这个新规定对TDX的使用量是没有影响的。

ossan

however, the change will not allow more TDX on fruit than was allowed in the 1960’s,
这个条例不会让水果上的tdx比60年代水果上的tdx多，因为这个新规定对TDX的使用量是没有影响的？

这个题目我就没弄懂 ~请nn指教啊

sdcar2010

It's a math problem with reading comprehension as a means.

Premise: In 1960's, fruit found with TDX on it will not be on sale.

The conclusion says the the new regulation (to allow certain fruit with TDX level lower than a standard to be on sale)  would not allow more TDX on fruit than allowed in 1960's.

The reason? In 1960's, the level of TDX can be detected on the fruit is higher than the standard chosen by the new regulation. In other words, fruits having TDX amount lower than the standard had already been on sale in 1960's.

ossan

Thanks!i ‘ve clear about that ,obvisously i ingore the word 'trace'.

drunkpiano

Thanks!i ‘ve clear about that ,obvisously i ingore the word 'trace'.

-- by 会员 ossan (2011/3/13 21:51:05)

是I'm clear about that吧……haha

Margarete7

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