prep 破解版-P1-3

yangluoya

The prairie vole, a small North American grassland rodent, breeds year-round, and a group of voles living together consists primarily of an extended family, often including two or more litters.  Voles commonly live in large groups from late autumn through winter; from spring through early autumn, however, most voles live in far smaller groups.  The seasonal variation in group size can probably be explained by a seasonal variation in mortality among young voles.

 

 

 Which of the following, if true, provides the strongest support for the explanation offered?

 

 

 (A) It is in the spring and early summer that prairie vole communities generally contain the highest proportion of young voles.

(B) Prairie vole populations vary dramatically in size from year to year.

(C) The prairie vole subsists primarily on broad-leaved plants that are abundant only in spring.

(D) Winters in the prairie voles' habitat are often harsh, with temperatures that drop well below freezing.

(E) Snakes, a major predator of young prairie voles, are active only from spring through early autumn.

答案是E，我选了D

答案是E，我选了D

原文说草原鼠群居和散居的季节性变化是由于小鼠的死亡率变化引起的。

D说，冬季生存环境恶劣。所以需要通过群居来保护小鼠。

E说，春天到早秋一种以小鼠为猎物的蛇活动频繁。就说明这个时期需要群居来保护小鼠，而跟原文所说的相反，不能解释原文。

[此贴子已经被作者于2007-7-14 15:04:54编辑过]

yangluoya

这个问题很弱智吗？可是我真是想不通啊。谁来帮帮我吧

yangluoya

help

MissNewMe

3. (24275-!-item-!-188;#058&000768)

The prairie vole, a small North American grassland rodent, breeds year-round, and a group of voles living together consists primarily of an extended family, often including two or more litters.  Voles commonly live in large groups from late autumn through winter; from spring through early autumn, however, most voles live in far smaller groups.  The seasonal variation in group size can probably be explained by a seasonal variation in mortality among young voles. 结论
支持就是支持结论/说明措施可行或者措施达目的

Which of the following, if true, provides the strongest support for the explanation offered?

(A) It is in the spring and early summer that prairie vole communities generally contain the highest proportion of young voles. 无关比较
(B) Prairie vole populations vary dramatically in size from year to year. 无关
(C) The prairie vole subsists primarily on broad-leaved plants that are abundant only in spring. 无关
(D) Winters in the prairie voles' habitat are often harsh, with temperatures that drop well below freezing. 完全无关内容
(E) Snakes, a major predator of young prairie voles, are active only from spring through early autumn. 他因加强, 季节也和原文对应, 正好说明了为什么这个时节野鼠数量少.

大草原的野鼠, 一种北美牧地的动物, 每年一轮的繁殖, 住在一起阔大家庭, 经常包括2窝以上. 野鼠经常从晚秋开始到冬天一大群的住在一起; 但是从春天到早秋, 大多数的野鼠小数目的在一起. group size的季节性变化可能是因为小野鼠死亡率的季节变化.

[此贴子已经被作者于2007-7-15 5:52:09编辑过]

yangluoya

终于明白了，E说相应季节蛇活动多，小鼠自然就少了。

脑子当掉了

snowofjune

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snowofjune

很tricky 啊，我一开始也是选D

蓝夕叶子

想太多的表现。。我开始也选D。。可是并没有证据表明天气和vole的死亡率有关系。

azhar

温度低不代表死亡率高啊，文章中没有提到。

蔬菜小丸子

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