恳求牛牛指正GWD5-Q6怀疑答案抓狂中

特仑苏爸爸

According to a theory advanced
    by researcher Paul Martin, the wave
    of species extinctions that occurred
Line    in North America about 11,000 years
 (5)    ago, at the end of the Pleistocene era,
can be directly attributed to the arrival
of humans, i.e., the Paleoindians, who
were ancestors of modern Native
Americans.  However, anthropologist
(10)    Shepard Krech points out that large
animal species vanished even in areas
where there is no evidence to demon-
strate that Paleoindians hunted them.
Nor were extinctions confined to large
(15)    animals:  small animals, plants, and
insects disappeared, presumably not
all through human consumption.  Krech
also contradicts Martin’s exclusion of
climatic change as an explanation by
(20)    asserting that widespread climatic
    change did indeed occur at the end of
    the Pleistocene.  Still, Krech attributes
secondary if not primary responsibility
for the extinctions to the Paleoindians,
(25)    arguing that humans have produced
local extinctions elsewhere.  But,
according to historian Richard White,
even the attribution of secondary
responsibility may not be supported
(30)    by the evidence.  White observes that
Martin’s thesis depends on coinciding
dates for the arrival of humans and the
    decline of large animal species, and
Krech, though aware that the dates
(35)    are controversial, does not challenge
them; yet recent archaeological
discoveries are providing evidence
that the date of human arrival was
much earlier than 11,000 years ago.

Q6:
Which of the following, if true, would most weaken Krech’s objections to Martin’s theory?
        
A.    Further studies showing that the climatic change that occurred at the end of the Pleistocene era was even more severe and widespread than was previously believed
B.    New discoveries indicating that Paleoindians made use of the small animals, plants, and insects that became extinct
C.    Additional evidence indicating that widespread climatic change occurred not only at the end of the Pleistocene era but also in previous and subsequent eras
D.    Researchers’ discoveries that many more species became extinct in North America at the end of the Pleistocene era than was previously believed
E.    New discoveries establishing that both the arrival of humans in North America and the wave of Pleistocene extinctions took place much earlier than 11,000 years ago

我选的是C，我觉得C的意思是气候变化长期存在，但是人类出现在 the end of the Pleistocene era，人类的出现是新的一个因素。而物种在当时灭绝了，不是正好削弱了Krech的Objection么（物种灭绝主要和气候变化有关，而不是人类活动）
正确答案B，意思不是说有正确显示人类利用了已经灭绝的小型动物什么的，那不就是说人类出现的时候那些物种已经灭绝了。那就支持了当时物种灭绝和人类活动无关（与气候有关）那不是support了K的观点了。

恳请牛牛指正，这两天题做多了，秀逗了。

hughlv

lz看来是做多题了，洗洗头吧。

B的意思是那时候的人类也在利用后来灭绝了的小动物（应该是抓来吃吧）。如果小动物在人类之前已经灭绝了，那人类还怎么make use of它们呢？这个选项直接证明了人类是在干涉小动物的生存现状的，所以weaken了Krech的论点。

从原文可得出，Krech认为气候是动物灭绝的原因（Krech also contradicts Martin’s exclusion of climatic change as an explanation ...，看清楚这句的意思是Martin不认为气候是灭绝的原因，但是Krech反对这个观点）。那么你要weaken他的观点应该是去证明气候不是灭绝的原因啊。

特仑苏爸爸

谢谢，正在洗头中。但是我还是觉得C还是有削弱作用的，只是没有B那么强。

hughlv

C里面的信息有一点需要看清楚就是，它讲的是气候变化也存在于其他的era，而不是说也存在于P era的其他阶段。假如是证明也存在于P era的其他阶段，那我也同意会起到一定的削弱作用：之前的没导致灭绝，那么这次也就没理由就灭了。但是文中并没有提其他era是否有灭绝的事情发生。有两种可能：

   1) 每次气候变化的时候都会导致动物灭绝从而导致一个era的结束。这样就是support。
   2) 气候变化在其他era未导致动物灭绝。可以起一定的削弱作用，但也不是很绝对。

因此，单凭C的证据是没法起削弱作用的。

edwardelric

http://forum.chasedream.com/GMAT_RC/thread-442910-1-1.html#13910679
你看看讨论贴吧