[求助]TT GWD-4-11????

Q11:

Because ethylene dibromide, a chemical used to fumigate
grain, was blamed for the high rate of nerve damage suffered by people who work
in grain-processing plants, many such plants switched to other chemical
fumigants two years ago.  Since then,
however, the percentage of workers at these plants who were newly diagnosed
with nerve damage has not dropped significantly.  Therefore, either ethylene dibromide was
wrongly blamed or else the new chemicals also cause nerve damage.

Which of the following is an assumption on which the
argument depends?

1. If the
        new chemicals cause nerve damage, the nerve damage caused would be
        different from any nerve damage that ethylene dibromide may cause.
2. There
        are no chemical fumigants that are completely safe for workers in
        grain-processing plants.
3. If
        ethylene dibromide causes nerve damage, it does not take two years or
        longer for that damage to become detectable.
4. Workers
        at grain-processing plants typically continue to work there even after
        being diagnosed with nerve damage.
5. Workers
        at grain-processing plants that still use ethylene dibromide continue to
        have a high rate of nerve damage.

  
Answer: C

我选了E,为什么E不行？E削弱如果那些still use ethylene dibromide的planrs没有高发病率的话不就说明可以判断是新农药 cause nerve damage吗？

it is talking about which one is the culprit, not which one is the least poison stuff.

A，如果都是致癌物，不能说带来的是不同的癌吧？狡辩，错。只要是会带来精神损伤，就不能否认致病的事实。

取非，两种精神损伤都差异，说明以前用的ED这个东东还是致病，摆脱不了干系。

迷惑选项。

B，fumigants that are completely safe，无关。题目在比较两者关系，该选项无关。

C，以前用的ED这个东东致病的话不会2年后才能被检查出来。

取非，如果以前的ED带来的后果要2年后才能检查出来，则后来那些得病的工人其实是以前ED带来的后遗症了，因此新的那个other chemical fumigants就可能是替人受过，被冤枉了。

D，工人状况，与两个东东的比较无关。

E，只谈到一种东东，与两个东东的比较无关。