prep逻辑题-Native American Camp

amodashikagome

Archaeologists in Michigan have excavated a Native American camp near Dumaw Creek.  Radiocarbon dating of animal bones found at the site indicates that the camp dates from some time between 1605 and 1755.  However, the camp probably dates to no later than 1630, since no European trade goods were found at the site, and European traders were active in the region from the 1620's onward.

Which of the following, if true, most strengthens the argument?

(A) Due to trade among Native Americans, some European trade goods would have reached the area before the European traders themselves did.   
(B) At all camps in the region that have been reliably dated to the late 1620's, remains of European trade goods have been found.  
(C) The first European trade goods to reach the area would have been considered especially valuable and preserved as much as possible from loss or destruction.
(D) The first European traders in the area followed soon after the first European explorers.
(E) The site is that of a temporary camp that would have been used seasonally for a few years and then abandoned.


要支持camp不晚于1630
A选项，如果goods比traders还要早到，而camp没有goods，时间岂不是远远早于1630呢。

francoisyang

原题问哪个选项成立可以加强“however, the camp probably dates to no later than 1630”。
A如果成立，导致camp在1620年之前出现的可能性大增，就会削弱“ the camp probably dates to no later than 1630”

amodashikagome

francoisyang 发表于 2014-2-14 15:24
原题问哪个选项成立可以加强“however, the camp probably dates to no later than 1630”。
A如果成立，导 ...

但是早于1620不属于no later than 1630吗

jackykangyi

我是这么理解的：
原文逻辑链：“1620年后有Etrade”且“camp无Etrade goods” —>camp不太可能在1630年之前。
A选项说E trade goods很早就有了，有些破坏原文逻辑链的左半部分，所以不好。
其实原文是用有E trade加上E trade goods来推理，这里明显隐藏一个假设，即有了E trade后必然能发现一些E trade goods，B说的正好是这个假设，所以是best answer。
本题Ron神也认为A起到了一点加强作用，但和B比，B更好。