求教两道Boldface题！GWD3-Q25&Q32

ayu2007126813

Q25:
Scientists typically do their most creative work before the age of forty.  It is commonly thought that this happens because aging by itself brings about a loss of creative capacity.  However, a study has found that almost all scientists who produce highly creative work beyond the age of forty entered their fields late and less than a dozen years before their creative breakthroughs.  Since creative breakthroughs by scientists under forty also generally occur within a dozen years of the scientist’s entry into the field, the study’s finding strongly suggests that the real reason why scientists over forty rarely produce highly creative work is not due to age but rather because most have spent too long in their fields.

In the argument given, the two portions in boldface play which of the following roles?

C.    The first is an explanation that the argument challenges; the second provides evidence in support of a competing explanation that the argument defends.
D.    The first is an explanation that the argument challenges; the second is evidence that has been used against an alternative explanation that the argument defends.

后半句，求解释~

GWD3-Q32
Q32:
Ecologist: The Scottish Highlands were once the site of extensive forests, butthese forests have mostly disappeared and been replaced by peat bogs.  The common view is that the Highlands’deforestation was caused by human activity, especially agriculture. However, agriculturebegan in the Highlands less than 2,000 years ago.  Peat bogs, which consist of compresseddecayed vegetable matter, build up by only about one foot per 1,000 years and, throughoutthe Highlands, remains of trees in peat bogs are almost all at depths greatthan four feet.  Since climatechanges that occurred between 7,000 and 4,000 years ago favored the developmentof peat bogs rather than the survival of forests, the deforestation was morelikely the result of natural processes than of human activity.
In the ecologist’s argument the twoportions in boldface play which of the following roles?

The first is evidence that has been used in support of a     position that the ecologist rejects; the second is a finding that the     ecologist uses to counter that evidence.
The first is evidence that, in light of the evidence provided     in the second, serves as grounds for the ecologist’s rejection of a     certain position.
The first is a position that the ecologist rejects; the second     is evidence that has been used in support of that position.
The first is a position that the ecologist rejects; the second     provides evidence in support of that rejection.
The first is a position for which the ecologist argues; the     second provides evidence to support that position.

  Answer: A  B

ayu2007126813

顶下！

法兰克福来客

Q25 选D吧？第二个黑体部分单看是什么都证明不了的，只有和前面一句比较，不管40岁以前还是以后，都是在进入这个领域12年内有创造性成就的，才推出和年龄无关的结论的。

法兰克福来客

Q32, 两个黑体之间是有联系的，农业开始于2000年内，而每1000年才产生1foot peat bogs，所以4 foot peat bogs 不是2000年内才开始形成的，而是更久以前就开始了，所以和农业无关。第二个黑体相当于给出计算方法，第一个则给出基于此种计算方法的证据。