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标题: 求助prep逻辑? 多谢 [打印本页]

作者: nst1308    时间: 2010-1-8 13:11
标题: 求助prep逻辑? 多谢
On Pacific islands, a newly arrived gecko species, the house gecko, is displacing the previously established mourning gecko in urban areas, but populations of the two species are more stable in rural areas far from human settlement.  The house gecko does not attack the mourning gecko, but in areas where insects congregate it prevents the mourning gecko from feeding on them.



Which of the following contributes most to an explanation of the difference between gecko populations in urban and rural areas?



(A) In urban areas, geckos are valued because they eat so many insects.

(B) Geckos defend territories against other members of the same species.

(C) House geckos that arrive on islands are carried there in boats and planes.

(D) In places where there are lighted buildings, insects tend to gather around the light.

(E) Mourning geckos are all females and reproduce asexually, but house geckos reproduce sexually.




答案选d,为什么?

作者: prayer    时间: 2010-1-8 13:59
题目说了一个新的动物来到这个岛上,造成城市里原来的那个动物没了,但是乡下还是有的。又说他们不互相攻击,但是在虫子聚集的地方,新来的跟以前的争食,不让以前的吃。
问题是解释为啥城市和乡下不一样,根据文章,应该是城里的那些原来的都饿死了,被新来的给干掉了,也就是说城市里虫子聚集的多。
D选项说,有光线的地方,虫子会聚集在光附近,这也是城里和乡下有差别的地方,城里光线多。
所以D对啊
作者: lxw19    时间: 2010-1-8 14:04
原文的意思就是说只要在有insects存在的地方,house gecko 与mourning gecko 就不能够“和平共处”,而正如D解释的那样,insects一般在light多的地方出没,也就是urban,因此城市里那些house gecko 为了食物与城市里的mourning gecko竞争,导致了mourning gecko 的渐渐消失, rural 地区light 少,insects不易被发现,所以正好解释了rural与urban的差别
作者: nst1308    时间: 2010-1-9 00:24
标题: 醍醐灌顶,谢谢
谢谢
作者: lala974    时间: 2011-7-2 04:27
up up




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