据资料介绍,在美国阿拉斯山的一个国家天然养鹿动物园里,无忧无虑的鹿群由于不必为食物发愁,不必为逃避敌害奔跑,结果病弱者越来越多,竟出现了危机。引进狼后,狼捕食了病弱者,切断了传染病之源,又迫使鹿群经常奔跑,体质日健,倒比以前繁盛多了。我想这个例子恐怕是再清晰不过地 According to the information, in a natural deer zoo in Mount Arlas in the United States, carefree deer do not have to worry about food because they do not have to run away from their enemies. As a result, more and more people are suffering from crises . After the introduction of the wolf, the wolf predators of the weak, cut off the source of infectious diseases, but also forced the deer often run, physical health, down more prosperous than before. I think this example is probably no more clear