关于狼和羊的经典题目的一个问题

pychina

Wolves generally avoid human settlements.  For this reason, domestic sheep, though essentially easy prey for wolves, are not usually attacked by them.  In Hylantia prior to 1910, farmers nevertheless lost considerable numbers of sheep to wolves each year.  Attributing this to the large number for wolves, in 1910 the government began offering rewards to hunters for killing wolves.  From 1910 to 1915, large numbers of wolves were killed.  Yet wolf attacks on sheep increased significantly.

 

Which of the following, if true, most helps to explain the increase in wolf attacks on sheep?

 

1. Populations of deer and other wild animals that wolves typically prey on increased significantly in numbers from 1910 to 1915.

2. Prior to 1910, there were no legal restrictions in Hylantia on the hunting of wolves.

3. After 1910 hunters shot and wounded a substantial number of wolves, thereby greatly diminishing these wolves’ ability to prey on wild animals.

4. Domestic sheep are significantly less able than most wild animals to defend themselves against wolf attacks.

5. The systematic hunting of wolves encouraged by the program drove many wolves in Hylantia to migrate to remote mountain areas uninhabited by humans.

本题选C,C可以解释同时也相关.但我想问的是A,因为A表达了狼的食物增多了,即狼的数量有可能增多(增多完全可能的比被杀的large number还多),同时虽然文章开头说狼不太可能攻击羊,但随后也给出了1910年大量羊被狼吃的事实,因此狼的数量因为"粮食"变多而变多,从而导致更多羊被攻击,也是一个充分的条件啊!!请教各位了!!

cloudymind

狼的食物增多了-->即狼的数量有可能增多--->增多数目的狼会吃羊

后面两个都是你的假设，同时不能解释 large numbers of wolves were killed.  Yet wolf attacks on sheep increased significantly.这个coorelationship.

pychina

这个不是假设吧,食物多了导致以此为食物的生物变多很正常啊.

虽然大量被杀,但是有更多的繁殖出来,总数加减后,依旧增多,导致狼攻击羊,似乎没什么问题啊

cloudymind

食物多了狼干吗还冒险去袭击羊群？袭击就说明天然野物不够。当然你可以argue狼增多的比鹿增多的还多，

但仔细想想，大量捕杀的时候，反而鹿也多了狼也多了，太牵强了吧。

[此贴子已经被作者于2007-12-14 7:58:36编辑过]

prayer

Wolves generally avoid human settlements关键在这一句。狼有捕猎其他动物的能力就会更加远离人类聚居区，只有丧失捕猎野生动物的能力才愿意冒险到人类聚居区吃羊。这是解释题，不是假设题