Q3. p2-cr 1. (24021-!-item-!-188;#058&000691)
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.
答案居然是D。。。。为什么啊，牛牛请教
在市區兩種gecko數目不平衡, 但是在郊區數目是穩定的. mourning gecko的食物是insect,house gecko在insect聚集的地方阻止了mourning以insect為食
很明顯mourning少了食物數量就會下降, 再加上題目排除了一種可能性就是house會攻擊mourning而導致mourning數量下降. 如果insect聚集的地方就是市區, 那麼mourning的數量應該是下降.
D中lighted building接近於urban areas, not rural areas far from human settlement, gather around=congregate
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