PT 58 1/24 一点都不明白这道题

lily88888UID: 2828533

The Kiffer Forest Preserve, in the northernmost part of the Abbimac Valley, is where ,most of the bears in the valley reside. During the eight years that the main road through the preserve has been closed the preserve's bear population has nearly doubled. Thus, the valley's bear population will increase if the road is kept closed.

Which one of the following, if true, most undermines the argument?

A Most of the increase in the preserve's bear population over the past night years is due to migration.
B. Only some of the increase in the preserve's bear population over the past eight years in due to migration of bears from other parts of the Abbimac Valley.
C. Only some of the increases in the preserve's bear population over the past eight years is due to migration of bears from outside the Abbimac Valley.
D. The bear population in areas of the Abbimac Valley outside the Kiffer Forest Preserve has decreased over the past eight years.
E. The bear population in the Abbimac Valley has remained about the same over the past eight years. (OA)
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D可以排除. ABC都谈到migration. 我想road close可能利于migration, 所以选了C。不知道D为什么能undermines the argument.

waimanUID: 2892309

(A)(B)(C) 都偏向支持,
(D) 无关
(E) 好难, 我看了半天, (E)说 Valley has remained反驳原文, 虽然KFP的熊增加两倍, 但Abbimac Valley不变, 破坏原文假设(封路可以增加数量)

waimanUID: 2892309

可能要住意scope shift, 英文太烂了, 一眼看不出, 唉唉唉

duijinxiaoziUID: 2585955

The bear population in the Abbimac Valley has remained about the same over the past eight years 基本= All of the increase in the preserve's bear population over the past night years is due to migration.
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题干：
Kiffer Forest Preserve  is where ,most of the bears in the valley reside.
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（E）说整体数量不变。说明 migration 是增加熊数量的主要动力（不是因为封路 或者 自己生小熊），而most的熊已经在Kiffer Forest Preserve 里面了。 所以，migration 使Preserve 里面熊数量增加可能性，就大大减少了。